Exhibit 99.1

Press Release Source: Ultra Clean Holdings, Inc.

Ultra Clean Holdings Reports Second Quarter Financial Results
Monday, July 25, 4:30 pm ET

UCT Expands Product Offering and Ships First Process Module.

MENLO PARK, Calif., July 25, 2005 /PRNewswire/ -- Ultra Clean Holdings, Inc. (Nasdaq: UCTT), a leading developer and supplier of critical subsystems for the semiconductor capital equipment industry, producing primarily gas delivery systems, today reported financial results for the second quarter ended June 30, 2005. The Company recorded revenue of $39.3 million and net income of $692,000 or $0.04 per share on a fully diluted basis, in line with company guidance. Among the highlights of the Company’s second quarter was the rapid growth in revenue generated by our facility in Shanghai, which was officially opened in the first quarter of 2005 and recently began producing and shipping gas panels to two customers. Additionally, the company continued to execute against the strategy to extend its product offering, with process module shipments made in the second quarter to a significant OEM customer.

Revenue for the second quarter of 2005 totaled $39.3 million, compared to revenue for the first quarter ended March 31, 2005 of $41.9 million, a decrease of 6.2% . Revenue for the second quarter decreased 27.9% compared to revenue of $54.5 million for the same period a year ago. The company recorded net income of $692,000, or $0.04 per share on a fully diluted basis, during the second quarter of 2005, compared to net income of $1.2 million, or $0.07 per share for the first quarter of 2005 and net income of $3.1 million, or $0.18 per share for the same period a year ago. Gross margin for the second quarter of 2005 was 14.2% versus 15.9% for the first quarter of 2005 and 16.4% for the same period a year ago.

Clarence Granger, UCT’s President and Chief Executive Officer, commented on the second quarter results: “We are very pleased that UCT’s second quarter revenues and earnings were in line with guidance, despite slower industry conditions. We are also pleased with several significant achievements during the second quarter: we made our first shipments of process modules as planned in the quarter; shipped products to two customers in volume out of our new facility in Shanghai, China; and expanded our frame assembly product offering to our current customer.”

Granger continued: “We have been very successful in completing sales of our non-gas panel, subassembly products, which reached $2.4 million in the second quarter of 2005, from $2.1million in the first quarter of 2005. We are continuing to focus on expanding our reach into the semiconductor process tool with the goal of becoming a more valued outsource supplier to our customers and the industry.”

Commenting on UCT’s corporate outlook, Granger noted, “Consistent with softness across the broader semiconductor capital equipment industry, we expect revenue for the third quarter of 2005 to be down sequentially to between $25 and $30 million, and net loss per share to range between $0.04 and $0.09. We have responded appropriately to softening industry demand by reducing headcount and inventory, and continue to advance our strategic positioning for long term growth.”

Ultra Clean will conduct a conference call on Monday, July 25, 2005, beginning at 2:00 p.m. PDT at 800/416-4612 (domestic) and 415/908-4730 (international). A replay of the webcast will be available for fourteen days following the conference call at 800/633-8284 (domestic) and 402/977-9140 (international). The confirmation number for the live broadcast and replays is 21251668 (all callers). The conference call will also be webcast live and be available for fourteen days on our website.

About Ultra Clean Holdings, Inc.

Ultra Clean Holdings, Inc. is a developer and supplier of critical subsystems for the semiconductor capital equipment industry, focusing on gas delivery systems. Ultra Clean offers its customers a complete outsourced solution for gas delivery systems and other subassemblies, improved design-to-delivery cycle times,

component neutral design and manufacturing and component testing capabilities. Ultra Clean's customers are primarily original equipment manufacturers of semiconductor capital equipment. Ultra Clean is headquartered in Menlo Park, California. Additional information is available at www.uct.com.

Safe Harbor Statement

The foregoing information contains, or may be deemed to contain, "forward- looking statements" (as defined in the U.S. 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," "believes," "plan," "expect," "future,"' "intends," "may," "will," "should," "estimates," "predicts," "potential," "continue" and similar expressions to identify these forward-looking statements. Forward looking statements included in the press release include estimates made with respect to our third quarter revenue and diluted loss per share. All forward-looking statements address matters that involve risks and uncertainties. Accordingly, our actual results may differ materially from the results predicted or implied by these forward- looking statements. These risks, uncertainties and other factors 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 31, 2004 and quarterly report on Form 10-Q for the quarter ended March 31, 2005, each 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.

ULTRA CLEAN HOLDINGS, INC.
CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS
(In thousands, except per share data)
(Unaudited)

	Three months ended June 30,					Six months ended June 30,
		2005		2004			2005		2004
Sales	$	39,289	$	54,508		$	81,213	$	95,345
Cost of goods sold		33,698		45,586			68,973		80,342
Gross profit		5,591		8,922			12,240		15,003
Operating expenses:
Research and development		749		661			1,436		1,213
Sales and marketing		864		941			1,758		1,645
General and administrative		2,807		2,099			6,118		3,575
Stock and other deferred compensation		53		52			105		656
Total operating expenses		4,473		3,753			9,417		7,089
Income from operations		1,118		5,169			2,823		7,914
Interest and other income (expense), net		28		(21	)		55		(411	)
Income before provision for income taxes		1,146		5,148			2,878		7,503
Income tax provision		454		2,059			992		3,001
Net income	$	692	$	3,089		$	1,886	$	4,502
Net income per share:
Basic	$	0.04	$	0.19		$	0.12	$	0.34
Diluted	$	0.04	$	0.18		$	0.11	$	0.32
Shares used in computing net income per
share
Basic		16,217		16,046			16,203		13,078
Diluted		17,227		17,204			17,116		13,996

ULTRA CLEAN HOLDINGS, INC.

CONDENSED CONSOLIDATED BALANCE SHEETS

(In thousands, except per share data)

	June 30,			December 31,
	2005			2004
ASSETS
Current assets:
Cash	$	11,292		$	11,440
Accounts receivable		17,170			13,785
Inventory		13,503			15,133
Other current assets		3,827			4,300
Total current assets		45,792			44,658
Equipment and leasehold improvements, net		4,934			5,392
Goodwill		6,617			6,617
Tradename		8,987			8,987
Other non-current assets		2,094			2,044
Total assets	$	68,424		$	67,698
LIABILITIES & STOCKHOLDERS' EQUITY
Current liabilities
Bank borrowings	$	2,326		$	-
Accounts payable		8,526			12,302
Other current liabilities		2,460			2,495
Total current liabilities		13,312			14,797
Capital lease obligations and other liabilities		386			426
Total liabilities		13,698			15,223
Commitments and contingencies
Stockholders' equity
Common stock		46,497			46,237
Deferred stock-based compensation		(466	)		(571	)
Retained earnings		8,695			6,809
Total stockholders' equity		54,726			52,475
Total liabilities and stockholders' equity	$	68,424		$	67,698

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Jack Sexton

VP & CFO

650/617-4121