-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 WTa5rDkn0Q3rQdjYdAorM8HDD57UQ2JrSrMiCpQ97pTwC+3J8lWNpVV14T+XkA+J
 nvRpZLEk4Zs8wZ/1cSL2DQ==

<SEC-DOCUMENT>0000000000-06-012897.txt : 20061013
<SEC-HEADER>0000000000-06-012897.hdr.sgml : 20061013
<ACCEPTANCE-DATETIME>20060316153337
<PRIVATE-TO-PUBLIC>
ACCESSION NUMBER:		0000000000-06-012897
CONFORMED SUBMISSION TYPE:	UPLOAD
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20060316

FILED FOR:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			KEITHLEY INSTRUMENTS INC
		CENTRAL INDEX KEY:			0000054991
		STANDARD INDUSTRIAL CLASSIFICATION:	INSTRUMENTS FOR MEAS & TESTING OF ELECTRICITY & ELEC SIGNALS [3825]
		IRS NUMBER:				340794417
		STATE OF INCORPORATION:			OH
		FISCAL YEAR END:			0930

	FILING VALUES:
		FORM TYPE:		UPLOAD

	BUSINESS ADDRESS:	
		STREET 1:		28775 AURORA RD
		CITY:			SOLON
		STATE:			OH
		ZIP:			44139
		BUSINESS PHONE:		2162480400
PUBLIC REFERENCE ACCESSION NUMBER:		0000950152-05-009956
</SEC-HEADER>
<DOCUMENT>
<TYPE>LETTER
<SEQUENCE>1
<FILENAME>filename1.txt
<TEXT>


Mail Stop 6010


March 16, 2006

Mr. Mark J. Plush
Vice President and Chief Financial Officer
Keithley Instruments, Inc.
28775 Aurora Road
Solon, Ohio 44139

		RE: 	Keithley Instruments, Inc.
			Form 10-K for fiscal year ended September 30, 2005
			File No.  1-9965

Dear Mr. Plush,

	We have completed our review of your Form 10-K and related
filings and do not, at this time, have any further comments.


      Sincerely,


							Martin F. James
							Senior Assistant Chief
Accountant

</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
-----END PRIVACY-ENHANCED MESSAGE-----