SEC Form 4

FORM 4		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0287 Estimated average burden hours per response: 0.5
X	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

1. Name and Address of Reporting Person* KEITHLEY JOSEPH P (Last) (First) (Middle) KEITHLEY INSTRUMENTS, INC. 28775 AURORA ROAD (Street) SOLON OH 44139 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol KEITHLEY INSTRUMENTS INC [ KEI ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner X Officer (give title below) Other (specify below) Director, Chairman, CEO
	3. Date of Earliest Transaction (Month/Day/Year) 11/04/2010
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Class B Common Shares	11/04/2010		G(1)		23,031	D	$0.00	23,031	I	Trust(1)(2)
Class B Common Shares	11/04/2010		G(1)		23,031	A	$0.00	23,031	I	Trust(1)
Class B Common Shares	11/04/2010		G(1)		23,031	D	$0.00	0	I	Trust
Class B Common Shares	12/08/2010		D(3)		23,031	D	$21.6	0	I	Trust(2)
Class B Common Shares	12/08/2010		D(3)		1,954,816	D	$21.6	0	I	Partnership(4)
Common Shares	12/08/2010		D(3)		91,298(5)	D	$21.6	0	D
Common Shares	12/08/2010		D(3)		2,448	D	$21.6	0	I	Wife

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares
Common Share Option	$18.41	12/08/2010		D(6)			100,000	07/25/2003(7)	07/24/2011	Common Shares	100,000	$3.19	0	D
Common Share Option	$13.76	12/08/2010		D(8)			100,000	07/24/2004(7)	07/23/2012	Common Shares	100,000	$7.84	0	D
Common Share Option	$16.12	12/08/2010		D(9)			100,000	08/10/2005	07/18/2013	Common Shares	100,000	$5.48	0	D
Common Share Option	$18.75	12/08/2010		D(10)			70,000	02/15/2005	07/16/2014	Common Shares	70,000	$2.85	0	D
Common Share Option	$15.05	12/08/2010		D(11)			55,000	10/04/2007(7)	10/03/2015	Common Shares	55,000	$6.55	0	D
Common Share Option	$9.12	12/08/2010		D(12)			38,300	11/09/2009(7)	11/09/2017	Common Shares	38,300	$12.48	0	D

Explanation of Responses:

1. 23,031 Class B Common Shares were gifted from the Joseph F. Keithley 1988 Trust to the Joseph F. Keithley 1988 Trust FBO Elizabeth M. Keithley of which reporting person is Trustee, and subsequently gifted to a charitable foundation.

2. Joseph F. Keithley 1988 Family Trust - reporting person is Trustee

3. Disposed of pursuant to an Agreement and Plan of Merger, dated as of September 29, 2010 (the "Merger Agreement") by and among Danaher Corporation, Aegean Acquisition Corp. and the Issuer in exchange for the merger consideration of $21.60 in cash per share.

4. Indirect ownership by Keithley Investment Co. Limited Partnership.

5. Includes 1,308 shares for which restrictions lapsed on December 1, 2010, which were previously reported as restricted shares.

6. The options were cancelled pursuant to the Merger Agreement in exchange for the merger consideration of $21.60 in cash per share, less the exercise price per share of $18.41.

7. Date reported applied to 50% of total, one-half of the balance was then exercisable in each succeeding year.

8. The options were cancelled pursuant to the Merger Agreement in exchange for the merger consideration of $21.60 in cash per share, less the exercise price per share of $13.76

9. The options were cancelled pursuant to the Merger Agreement in exchange for the merger consideration of $21.60 in cash per share, less the exercise price per share of $16.12.

10. The options were cancelled pursuant to the Merger Agreement in exchange for the merger consideration of $21.60 in cash per share, less the exercise price per share of $18.75.

11. The options were cancelled pursuant to the Merger Agreement in exchange for the merger consideration of $21.60 in cash per share, less the exercise price per share of $15.05.

12. The options were cancelled pursuant to the Merger Agreement in exchange for the merger consideration of $21.60 in cash per share, less the exercise price per share of $9.12.

Remarks:

	Mark J. Plush, Attorney-in Fact	12/09/2010
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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