2008-05-09 22:23:08 -

- Keithley Instruments, Inc. (NYSE:KEI), a leader in solutions for emerging measurement needs, today announced its regular quarterly cash dividend of $0.0375 per Common Share. The dividend is payable June 30, 2008, to shareholders of record at the close of business on June 16, 2008.

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 from DC to RF (radio frequency). Our products solve emerging measurement needs in production testing, process monitoring, product development, and research. 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 precision measurement technology 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
Vice President and Chief Financial Officer
Fax: 440-248-6168
www.keithley.com