FORM 4 Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP OF SECURITIES Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940

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1. Name and Address of Reporting Person * ETSLER PHILIP   2. Issuer Name and Ticker or Trading Symbol KEITHLEY INSTRUMENTS INC [KEI] 5. Relationship of Reporting Person(s) to Issuer (Check all applicable) _____ Director _____ 10% Owner __X__ Officer (give title below) _____ Other (specify below) VP Human Resources (Last) (First) (Middle) KEITHLEY INSTRUMENTS, INC., 28775 AURORA ROAD 3. Date of Earliest Transaction (Month/Day/Year) 05/11/2007 (Street) SOLON, OH 44139 4. If Amendment, Date 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 (City) (State) (Zip) 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 Common Shares 03/30/2007   J(1)   84 A $ 15.1899 36,533 D   Common Shares 05/11/2007   S   400 D $ 12.01 36,133 D   Common Shares 05/11/2007   S   100 D $ 12.03 36,033 D   Common Shares 05/11/2007   S   1,500 D $ 12.04 34,533 D   Common Shares 05/11/2007   S   2,500 D $ 12.05 32,033 D   Common Shares 05/11/2007   S   100 D $ 12.06 31,933 D   Common Shares 05/11/2007   S   740 D $ 12.09 31,193 D   Common Shares 05/11/2007   S   200 D $ 12.1 30,993 D   Common Shares 05/11/2007   S   600 D $ 12.12 30,393 D   Common Shares 05/11/2007   S   200 D $ 12.13 30,193 D   Common Shares 05/11/2007   S   500 D $ 12.16 29,693 D   Common Shares 05/11/2007   S   300 D $ 12.17 29,393 D   Common Shares 05/11/2007   S   760 D $ 12.18 28,633 D   Common Shares 05/11/2007   S   400 D $ 12.2 28,233 D   Common Shares 05/11/2007   S   240 D $ 12.21 27,993 D   Common Shares 05/11/2007   S   100 D $ 12.24 27,893 D   Restricted Common Shares (2)               6,016 D

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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 Underlying Securities (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 of Derivative Security: 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

$ 45.125

08/02/2002

08/01/2010

Common Shares

24,000

24,000

D

Common Share Option

$ 18.41

07/25/2003(3)

07/24/2011

Common Shares

22,000

22,000

D

Common Share Option

$ 13.76

07/24/2004(4)

07/23/2012

Common Shares

22,000

22,000

D

Common Share Option

$ 16.12

08/10/2005(5)

07/18/2013

Common Shares

24,000

24,000

D

Common Share Option

$ 18.75

02/15/2005(3)

07/16/2014

Common Shares

21,000

21,000

D

Common Share Option

$ 15.05

10/04/2007(4)

10/03/2015

Common Shares

6,400

6,400

D

Performance Award Unit

$ 0

09/30/2008

02/01/2012

Common Shares

5,000 (6)

5,000 (6)

D

Performance Award Unit

$ 0

09/30/2009

02/01/2012

Common Shares

4,000 (6)

4,000 (6)

D

Reporting Owners

Reporting Owner Name / Address	Relationships
	Director	10% Owner	Officer	Other
ETSLER PHILIP KEITHLEY INSTRUMENTS, INC. 28775 AURORA ROAD SOLON, OH 44139			VP Human Resources

Signatures

Mark J. Plush, Attorney-in Fact		05/15/2007
**Signature of Reporting Person		Date

Explanation of Responses:

*	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).
(1)	Acquired through Employee Stock Purchase and Dividend Reinvestment Plan.
(2)	Restricted Shares will become fully vested on January 1, 2012
(3)	Option became fully vested on February 15, 2005
(4)	Date reported applies to 50% of total, one-half of the balance is then exercisable in each succeeding year.
(5)	Option became fully vested on August 10, 2005
(6)	Each Performance Award Unit represents the right to receive one common share at the end of the applicable performance period. The number of units actually earned is subject to adjustment based upon the Company's revenue growth versus that of a defined Peer Group, as well as the Company maintaining an acceptable level of profitability. Minimum number of units is 0 while the maximum number of units is two times the target number shown.

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