Keithley Instruments, Inc. (NYSE:KEI), a world leader in advanced electrical test instruments and systems, announced that its Board of Directors declared a quarterly cash dividend of $0.0375 per Common Share. This represented an increase from $0.0125 to $0.0375 per share. The quarterly dividend increased from $0.01 to $0.03 per Class B Common Share. The dividend is payable June 30, 2010, to shareholders of record at the close of business on June 16, 2010.

The Company's Chairman, President, and Chief Executive Officer, Joseph P. Keithley stated, ?We are pleased to have restored our dividend to year-ago levels as it reflects the Company's improved financial condition and our confidence in its continued financial and operational performance.?

About Keithley Instruments, Inc.

With more than 60 years of measurement expertise, Keithley Instruments has become a world leader in advanced electrical test instruments and systems. Our customers are scientists and engineers in the worldwide electronics industry involved with advanced materials research, semiconductor device development and fabrication, and the production of end products such as portable wireless devices. The value we provide them is a combination of products for their critical measurement needs and a rich understanding of their applications to improve the quality of their products and reduce their cost of test.

Keithley Instruments, Inc.
Mark J. Plush, 440-248-0400
Senior Vice President and Chief Financial Officer
Fax: 440-248-6168
http://www.keithley.com