Exhibit 99.1

Press Release Source: Ultra Clean Holdings, Inc.

Ultra Clean Reports Second Quarter 2021 Financial Results

HAYWARD, Calif., August 2, 2021 /PRNewswire/ Ultra Clean Holdings, Inc. (Nasdaq: UCTT), today reported its financial results for the second quarter ended June 25, 2021.

"UCT delivered strong second quarter results driven by disciplined execution in a robust demand environment across all of our end markets,” said Jim Scholhamer, CEO. “These results demonstrate that UCT’s diversified suite of capabilities and ability to deliver are enabling us to play a larger, more valuable role in the semiconductor ecosystem”.

Second Quarter 2021 GAAP Financial Results

Total revenue was $515.2 million. Products contributed $442.5 million and Services added $72.7 million. Total gross margin was 19.4%, operating margin was 6.2%, and net income was $17.1 million or $0.39 per basic and diluted share. This compares to total revenue of $417.6 million, gross margin of 20.8%, operating margin of 9.7%, and net income of $25.0 million or $0.62 and $0.60 per basic and diluted share in the prior quarter.

Second Quarter 2021 Non-GAAP Financial Results

On a non-GAAP basis, gross margin was 21.2%, operating margin was 11.7%, and net income was $43.7 million or $0.99 per diluted share. This compares to gross margin of 21.3%, operating margin of 12.2%, and net income of $38.2 million or $0.92 per diluted share in the prior quarter.

Third Quarter 2021 Outlook

The Company expects revenue in the range of $520.0 million to $560.0 million and GAAP diluted net income per share to be between $0.68 and $0.85. The Company expects non-GAAP diluted net income per share to be between $0.94 and $1.10.

Conference Call

The call will take place on Monday August 2, 2021 at 1:30 p.m. PT (4:30 pm ET) and can be accessed by dialing 1-844-826-3034 or 1-412-317-5179. No passcode is required. A replay of the call will be available by dialing 1-877-344-7529 or 1-412-317-0088 and entering the confirmation code 10158101. The Webcast will be available on the Investor Relations section of the Company's website at http://uct.com/investors/events/.  

About Ultra Clean Holdings, Inc.

Ultra Clean Holdings, Inc. is a leading developer and supplier of critical subsystems, components and parts, and ultra-high purity cleaning and analytical services primarily for the semiconductor industry. Under its Products division, UCT offers its customers an integrated outsourced solution for major subassemblies, improved design-to-delivery cycle times, design for manufacturability, prototyping, and high-precision manufacturing. Under its Services Division, UCT offers its customers tool chamber parts cleaning and coating, as well as micro-contamination analytical services. Ultra Clean is headquartered in Hayward, California. Additional information is available at www.uct.com.

Use of Non-GAAP Measures

In addition to providing results that are determined in accordance with Generally Accepted Accounting Principles in the United States of America (GAAP), management uses non-GAAP gross margin, non-GAAP operating margin and non-GAAP net income to evaluate the Company's operating and financial results. We believe the presentation of non-GAAP results is useful to investors for analyzing our core business and business trends and comparing performance to prior periods, along with enhancing investors' ability to view the Company's results from management's perspective. The presentation of this additional information should not be considered a substitute for results prepared in accordance with GAAP. Tables presenting reconciliations from GAAP results to non-GAAP results are included at the end of this press release.

The Company currently defines non-GAAP net income as net income (loss) before amortization of intangible assets, restructuring charges, executive transition costs, acquisition costs, fair value adjustments, depreciation adjustments, stock-based compensation, certain insurance proceeds, and the tax effects of the foregoing adjustments.

A reconciliation of our guidance for non-GAAP net income per diluted share for the subsequent quarter is not available due to fluctuations in the geographic mix of our earnings from quarter to quarter, which impacts our tax rate and cannot be reasonably predicted or determined. As a result, such reconciliation is not available without unreasonable efforts and we are unable to determine the probable significance of the unavailable information.

Safe Harbor Statement

The foregoing information contains, or may be deemed to contain, "forward-looking statements" (as defined in the US Private Securities Litigation Reform Act of 1995) which reflect our current views with respect to future events and financial performance. We use words such as "anticipates," “projection,” “outlook,” “forecast,” "believes," "plan," "expect," "future," "intends," "may," "will," "estimates," “see,” "predicts," “should” and similar expressions to identify these forward-looking statements. Forward looking statements included in this press release include our expectations about the semiconductor capital equipment market and outlook. All forward-looking statements address matters that involve risks and uncertainties. Accordingly, the Company’s actual results may differ materially from the results predicted or implied by these forward-looking statements. These risks, uncertainties and other factors also include, among others, those identified in "Risk Factors,” "Management's Discussion and Analysis of Financial Condition and Results of Operations'' and elsewhere in our annual report on Form 10-K for the year ended December 25, 2020 as filed with the Securities and Exchange Commission. Ultra Clean Holdings, Inc. undertakes no obligation to publicly update or review any forward-looking statements, whether as a result of new information, future developments or otherwise unless required by law.

Contact:

Rhonda Bennetto, Vice President Investor Relations

rbennetto@uct.com

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS

(Unaudited; in thousands, except per share data)

	Three Months Ended						Six Months Ended
	June 25,			June 26,			June 25,			June 26,
	2021			2020			2021			2020
Revenues:
Product	$	442,515		$	277,892		$	788,131		$	537,275
Services		72,685			66,890			144,696			128,403
Total revenues		515,200			344,782			932,827			665,678
Cost of revenues:
Product		367,919			229,276			651,488			444,031
Services		47,398			41,628			94,518			82,107
Total cost of revenues		415,317			270,904			746,006			526,138
Gross profit		99,883			73,878			186,821			139,540
Operating expenses:
Research and development		6,066			3,827			10,274			7,251
Sales and marketing		12,652			5,876			20,260			11,668
General and administrative		49,218			33,350			83,930			67,247
Total operating expenses		67,936			43,053			114,464			86,166
Income from operations		31,947			30,825			72,357			53,374
Interest income		59			158			157			470
Interest expense		(7,059	)		(3,773	)		(10,664	)		(8,961	)
Other income (expense), net		(711	)		560			(4,974	)		(2,131	)
Income before provision for income taxes		24,236			27,770			56,876			42,752
Provision for income taxes		6,221			5,691			13,236			10,156
Net income		18,015			22,079			43,640			32,596
Less: Net income attributable to noncontrolling interests		917			815			1,545			1,910
Net income attributable to UCT	$	17,098		$	21,264		$	42,095		$	30,686
Net income per share attributable to UCT common stockholders:
Basic	$	0.39		$	0.53		$	1.00		$	0.77
Diluted	$	0.39		$	0.52		$	0.98		$	0.75
Shares used in computing net income per share:
Basic		43,328			40,087			41,946			39,952
Diluted		44,253			40,834			42,948			40,774

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(Unaudited; in thousands)

	June 25,		December 25,
	2021		2020
ASSETS
Current assets:
Cash and cash equivalents	$	451,401	$	200,274
Accounts receivable, net of allowance		210,426		145,539
Inventories		301,956		180,385
Prepaid expenses and other current assets		35,506		18,895
Total current assets		999,289		545,093
Property, plant and equipment, net		218,295		159,150
Goodwill		257,179		171,132
Intangibles assets, net		270,518		160,519
Deferred tax assets, net		23,288		23,513
Operating lease right-of-use assets		69,809		37,821
Other non-current assets		8,277		5,315
Total assets	$	1,846,655	$	1,102,543
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities:
Bank borrowings	$	21,594	$	7,361
Accounts payable		231,002		121,328
Accrued compensation and related benefits		43,911		34,532
Operating lease liabilities		15,966		11,721
Other current liabilities		42,487		26,335
Total current liabilities		354,960		201,277
Bank borrowings, net of current portion		573,116		261,619
Deferred tax liabilities		45,497		33,571
Operating lease liabilities		54,274		31,050
Other liabilities		30,088		23,812
Total liabilities		1,057,935		551,329
Equity:
UCT stockholders’ equity:
Common stock		502,873		309,589
Retained earnings		260,067		217,972
Accumulated other comprehensive gain		4,586		5,087
Total UCT stockholders' equity		767,526		532,648
Noncontrolling interest		21,194		18,566
Total equity		788,720		551,214
Total liabilities and stockholders' equity	$	1,846,655	$	1,102,543

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS

(Unaudited; in thousands)

	Six Months Ended
	June 25,			June 26,
	2021			2020
Cash flows from operating activities:
Net income	$	43,640		$	32,596
Adjustments to reconcile net income to net cash provided by operating activities (excluding assets acquired and liabilities assumed):
Depreciation and amortization		30,906			23,403
Stock-based compensation		7,169			6,150
Deferred income taxes		877			(17	)
Change in the fair value of financial instruments		12,987			4,186
Gain from insurance proceeds		(7,332	)		—
Others		231			(239	)
Changes in assets and liabilities:
Accounts receivable		(13,254	)		(26,040	)
Inventories		(41,271	)		(21,459	)
Prepaid expenses and other current assets		(328	)		(1,567	)
Other non-current assets		(713	)		290
Accounts payable		80,768			6,520
Accrued compensation and related benefits		(1,084	)		2,832
Operating lease assets and liabilities		(575	)		(510	)
Income taxes payable		948			4,887
Other liabilities		3,756			2,153
Net cash provided by operating activities		116,725			33,185
Cash flows from investing activities:
Purchases of property, plant and equipment		(22,702	)		(17,049	)
Proceeds from sale of equipment, including insurance proceeds		7,399			2,922
Acquisition of business, net of cash acquired		(355,155	)		—
Net cash used in investing activities		(370,458	)		(14,127	)
Cash flows from financing activities:
Proceeds from bank borrowings		371,486			60,478
Proceeds from issuance of common stock		193,138			260
Principal payments on bank borrowings and finance leases		(43,370	)		(26,261	)
Payments of debt issuance costs		(8,899	)		—
Employees’ taxes paid upon vesting of restricted stock units		(7,013	)		(1,382	)
Others		(128	)		—
Net cash provided by financing activities		505,214			33,095
Effect of exchange rate changes on cash and cash equivalents		(354	)		(320	)
Net increase in cash and cash equivalents		251,127			51,833
Cash and cash equivalents at beginning of period		200,274			162,531
Cash and cash equivalents at end of period	$	451,401		$	214,364

ULTRA CLEAN HOLDINGS, INC.
REPORTABLE SEGMENTS
GAAP TO NON-GAAP RECONCILIATION
(Unaudited; dollars in thousands)
	GAAP									Non-GAAP
	Three Months Ended									Three Months Ended
	June 25, 2021									June 25, 2021
	Products			Services			Consolidated			Products			Services			Consolidated
Revenues	$	442,515		$	72,685		$	515,200		$	442,515		$	72,685		$	515,200
Gross profit	$	74,596		$	25,287		$	99,883		$	83,052		$	26,309		$	109,361
Gross margin		16.9	%		34.8	%		19.4	%		18.8	%		36.2	%		21.2	%
Income from operations	$	24,023		$	7,924		$	31,947		$	48,297		$	12,133		$	60,430
Operating margin		5.4	%		10.9	%		6.2	%		10.9	%		16.7	%		11.7	%

	Three Months Ended
	June 25, 2021
	Products			Services			Consolidated
Reconciliation of GAAP Gross profit to Non-GAAP Gross profit (in thousands)
Reported gross profit on a GAAP basis	$	74,596		$	25,287		$	99,883
Amortization of intangible assets (1)		658			1,022			1,680
Restructuring charges (2)		201			-			201
Stock-based compensation expense (3)		414			-			414
Fair value related adjustments (4)		7,183						7,183
Non-GAAP gross profit	$	83,052		$	26,309		$	109,361
Reconciliation of GAAP Gross margin to Non-GAAP Gross margin
Reported gross margin on a GAAP basis		16.9	%		34.8	%		19.4	%
Amortization of intangible assets (1)		0.1	%		1.4	%		0.3	%
Restructuring charges (2)		0.1	%		-			0.0	%
Stock-based compensation expense (3)		0.1	%		-			0.1	%
Fair value related adjustments (4)		1.6	%		-			1.4	%
Non-GAAP gross margin		18.8	%		36.2	%		21.2	%
Reconciliation of GAAP Income from operations to Non-GAAP Income from operations (in thousands)
Reported income from operations on a GAAP basis	$	24,023		$	7,924		$	31,947
Amortization of intangible assets (1)		5,795			3,716			9,511
Restructuring charges (2)		(68	)		40			(28	)
Stock-based compensation expense (3)		3,271			453			3,724
Fair value related adjustments (4)		7,183			-			7,183
Acquisition related costs (5)		8,093			-			8,093
Non-GAAP income from operations	$	48,297		$	12,133		$	60,430
Reconciliation of GAAP Operating margin to Non-GAAP Operating margin
Reported operating margin on a GAAP basis		5.4	%		10.9	%		6.2	%
Amortization of intangible assets (1)		1.3	%		5.1	%		1.8	%
Restructuring charges (2)		0.0	%		0.1	%		0.0	%
Stock-based compensation expense (3)		0.8	%		0.6	%		0.7	%
Fair value related adjustments (4)		1.6	%		0.0	%		1.4	%
Acquisition related costs (5)		1.8	%		0.0	%		1.6	%
Non-GAAP operating margin		10.9	%		16.7	%		11.7	%

1	Amortization of intangible assets related to the Company's business acquisitions
2	Represents severance, retention and costs related to facility closures
3	Represents compensation expense for stock granted to employees and directors
4	Represents acquisition fair value related adjustments
5	Represents costs related to the acquisition of Ham-Let

ULTRA CLEAN HOLDINGS, INC.
UNAUDITED RECONCILIATION OF GAAP TO NON-GAAP ADJUSTED RESULTS
	Three Months Ended
	June 25,			June 26,			March 26,
	2021			2020			2021
Reconciliation of GAAP Net Income to Non-GAAP Net Income (in thousands)
Reported net income attributable to UCT on a GAAP basis	$	17,098		$	21,264		$	24,997
Amortization of intangible assets (1)		9,511			4,949			4,889
Restructuring charges (2)		(28	)		1,572			140
Stock-based compensation expense (3)		3,724			3,104			4,043
Fair value related adjustments (4)		8,583			1,209			11,582
Acquisition related costs (5)		8,093			-			1,337
Insurance proceeds (6)		-			-			(7,332	)
Income tax effect of non-GAAP adjustments (7)		(5,259	)		(2,037	)		(2,639	)
Income tax effect of valuation allowance (8)		1,956			470			1,140
Non-GAAP net income attributable to UCT	$	43,678		$	30,531		$	38,157
Reconciliation of GAAP Income from operations to Non-GAAP Income from operations (in thousands)
Reported income from operations on a GAAP basis	$	31,947		$	30,825		$	40,410
Amortization of intangible assets (1)		9,511			4,949			4,889
Restructuring charges (2)		(28	)		1,572			140
Stock-based compensation expense (3)		3,724			3,104			4,043
Fair value related adjustments (4)		7,183			-			-
Acquisition related costs (5)		8,093			-			1,337
Non-GAAP income from operations	$	60,430		$	40,450		$	50,819
Reconciliation of GAAP Operating margin to Non-GAAP Operating margin
Reported operating margin on a GAAP basis		6.2	%		8.9	%		9.7	%
Amortization of intangible assets (1)		1.8	%		1.4	%		1.2	%
Restructuring charges (2)		0.0	%		0.5	%		0.0	%
Stock-based compensation expense (3)		0.7	%		0.9	%		1.0	%
Fair value related adjustments (4)		1.4	%		0.0	%		0.0	%
Acquisition related costs (5)		1.6	%		0.0	%		0.3	%
Non-GAAP operating margin		11.7	%		11.7	%		12.2	%
Reconciliation of GAAP Gross profit to Non-GAAP Gross profit (in thousands)
Reported gross profit on a GAAP basis	$	99,883		$	73,878		$	86,938
Amortization of intangible assets (1)		1,680			1,022			1,022
Restructuring charges (2)		201			253			6
Stock-based compensation expense (3)		414			726			980
Fair value related adjustments (4)		7,183			-			-
Non-GAAP gross profit	$	109,361		$	75,879		$	88,946
Reconciliation of GAAP Gross margin to Non-GAAP Gross margin
Reported gross margin on a GAAP basis		19.4	%		21.4	%		20.8	%
Amortization of intangible assets (1)		0.3	%		0.3	%		0.3	%
Restructuring charges (2)		0.0	%		0.1	%		0.0	%
Stock-based compensation expense (3)		0.1	%		0.2	%		0.2	%
Fair value related adjustments (4)		1.4	%		0.0	%		0.0	%
Non-GAAP gross margin		21.2	%		22.0	%		21.3	%

Reconciliation of GAAP Interest and other income (expense) to Non-GAAP Interest and other income (expense) (in thousands)
Reported interest and other income (expense) on a GAAP basis	$	(7,711	)	$	(3,055	)	$	(7,770	)
Fair value related adjustments (4)		1,400			1,209			11,582
Insurance proceeds (6)		-			-			(7,332	)
Non-GAAP interest and other income (expense)	$	(6,311	)	$	(1,846	)	$	(3,520	)
Reconciliation of GAAP Earnings Per Diluted Share to Non-GAAP Earnings Per Diluted Share
Reported net income on a GAAP basis	$	0.39		$	0.52		$	0.60
Amortization of intangible assets (1)		0.22			0.12			0.12
Restructuring charges (2)		(0.00	)		0.04			0.00
Stock-based compensation expense (3)		0.09			0.08			0.10
Fair value related adjustments (4)		0.19			0.03			0.28
Acquisition related costs (5)		0.18			-			0.03
Insurance proceeds (6)		-			-			(0.18	)
Income tax effect of non-GAAP adjustments (7)		(0.12	)		(0.05	)		(0.06	)
Income tax effect of valuation allowance (8)		0.04			0.01			0.03
Non-GAAP net income	$	0.99		$	0.75		$	0.92
Weighted average number of diluted shares (thousands) on a non-GAAP basis		44,253			40,834			41,639

ULTRA CLEAN HOLDINGS, INC.
UNAUDITED RECONCILIATION OF GAAP TO NON-GAAP EFFECTIVE INCOME TAX RATE
	Three Months Ended
	June 25,			June 26,			March 26,
	2021			2020			2021
(in thousands, except percentages)
Provision for income taxes on a GAAP basis	$	6,221		$	5,691		$	7,015
Income tax effect of non-GAAP adjustments (7)		5,259			2,037			2,639
Income tax effect of valuation allowance (8)		(1,956	)		(470	)		(1,140	)
Non-GAAP provision for income taxes	$	9,524		$	7,258		$	8,514
Income (loss) before income taxes on a GAAP basis	$	24,236		$	27,770		$	32,640
Amortization of intangible assets (1)		9,511			4,949			4,889
Restructuring charges (2)		(28	)		1,572			140
Stock-based compensation expense (3)		3,724			3,104			4,043
Fair value related adjustments (4)		8,583			1,209			11,582
Acquisition related costs (5)		8,093			-			1,337
Insurance proceeds (6)		-			-			(7,332	)
Non-GAAP income before income taxes	$	54,119		$	38,604		$	47,299
Effective income tax rate on a GAAP basis		25.7	%		20.5	%		21.5	%
Non-GAAP effective income tax rate		17.6	%		18.8	%		18.0	%

1	Amortization of intangible assets related to the Company's business acquisitions
2	Represents severance, retention and costs related to facility closures
3	Represents compensation expense for stock granted to employees and directors
4	Represents acquisition related fair value adjustments and fair value adjustments of contingent consideration, purchase obligation and forward hedge contracts
5	Represents costs related to acquisitions
6	Insurance proceeds pertaining to the Cinos fire in 2018
7	Tax effect of items (1) through (6) above based on the non-GAAP tax rate shown below
8	The Company's GAAP tax expense is generally higher than the Company's non-GAAP tax expense, primarily due to losses in the U.S. with full federal and state valuation allowances. The Company's non-GAAP tax rate and resulting non-GAAP tax expense considers the tax implications as if there was no federal or state valuation allowance position in effect.