Ownership Submission
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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(Print or Type Responses)
1. Name and Address of Reporting Person *
KEITHLEY JOSEPH P
   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
(Last)
(First)
(Middle)
KEITHLEY INSTRUMENTS, INC., 28775 AURORA ROAD		 3. Date of Earliest Transaction (Month/Day/Year)
04/20/2009
(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
Class B Common Shares               1,954,816 I Partnership (1)
Class B Common Shares               46,062 I Trust (2)
Class B Common Shares               130,000 D  
Common Shares 04/20/2009   P(3)   1,500 A $ 3.3733 (4) 77,891 D  
Common Shares 04/21/2009   P(3)   1,520 A $ 3.1901 (5) 79,411 D  
Restricted Common Shares (6)               2,616 D  
Common Shares               2,448 I Wife

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
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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 120,000   120,000 D  
Common Share Option $ 18.41             07/25/2003(7) 07/24/2011 Common Shares 100,000   100,000 D  
Common Share Option $ 13.76             07/24/2004(7) 07/23/2012 Common Shares 100,000   100,000 D  
Common Share Option $ 16.12             08/10/2005 07/18/2013 Common Shares 100,000   100,000 D  
Common Share Option $ 18.75             02/15/2005 07/16/2014 Common Shares 70,000   70,000 D  
Common Share Option $ 15.05             10/04/2007(7) 10/03/2015 Common Shares 55,000   55,000 D  
Common Share Option $ 9.12             11/09/2009(7) 11/09/2017 Common Shares 38,300   38,300 D  
Performance Award Unit $ 0             09/30/2010(8)   (8) Common Shares 19,300 (8)   19,300 (8) D  

Reporting Owners

Reporting Owner Name / Address Relationships
 Director  10% Owner  Officer  Other
KEITHLEY JOSEPH P
KEITHLEY INSTRUMENTS, INC.
28775 AURORA ROAD
SOLON, OH 44139		   X   X   Director, Chairman, CEO  

Signatures

 Mark J. Plush, Attorney-in Fact   04/21/2009
**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) Keithley Investment Co. Limited Partnership
(2) Joseph F. Keithley 1988 Family Trust - reporting person is Trustee
(3) The purchases reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 12, 2009.
(4) The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.35 to $3.40, inclusive. The reporting person undertakes to provide to Keithley Instruments, any security holder of Keithley Instruments, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote 4 to this Form 4.
(5) The price reported in Column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $3.17 to $3.20, inclusive. The reporting person undertakes to provide to Keithley Instruments, any security holder of Keithley Instruments, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in footnote 5 to this Form 4.
(6) Restricted shares will become fully vested on December 1, 2010
(7) Date reported applies to 50% of total, one-half of the balance is then exercisable in each succeeding year.
(8) Each Performance Award Unit represents the right to receive one common share. The number of units initially awarded, the target, is shown above. The actual number of units that will be awarded and converted to shares is based upon: a) the Company's revenue growth as compared to a defined Peer Group and, b) the Company maintaining an acceptable level of profitability during the performance period which ends on the date exercisable (the "vesting date"). Awarded units are automatically converted to shares under the Plan on or before the December 31st following the Vesting Date.

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