Keithley Instruments Deemed in Compliance with Continued Listing Standards by New York Stock Exchange

Keithley Instruments, Inc. (NYSE: KEI), a world leader in advanced electrical test instruments and systems, today announced that the New York Stock Exchange ("NYSE”) has notified the Company that it is deemed to be in compliance with the NYSE continued listing requirements. The NYSE recently modified its continued listing requirements for minimum market capitalization and stockholders’ equity to $50 million from $75 million.

The NYSE received approval from the Securities and Exchange Commission for a pilot program, effective retroactively to May 12, 2009, that modifies these continued listing requirements through October 31, 2009. The NYSE has indicated that it anticipates making a subsequent rule filing with the SEC prior to that date to make the rule change permanent. The Company’s market capitalization exceeded the $50 million threshold at the May 12, 2009 effective date, so the NYSE has removed the ".BC” suffix that signified that the Company was not in compliance with the NYSE continued listing standards.

The Company previously announced that it was notified by the NYSE that it had fallen below continued listing criteria established by the NYSE because the Company’s total market capitalization had been less than $75 million over a consecutive 30 trading-day period, while its last reported shareholders’ equity was less than the exchange’s $75 million requirement. The NYSE had previously notified the Company that it had accepted the Company’s proposed plan for continued listing on the NYSE, subject to a quarterly review process by the NYSE.

Forward-Looking Statements

Statements in this release that are not historical facts, including those relating to compliance with the NYSE’s continued listing requirements, are "forward-looking statements”, as defined in the Private Securities Litigation Reform Act of 1995, that involve a number of risks and uncertainties. Actual results may differ materially from the results stated or implied in the forward-looking statements as a result of a number of factors that include, but are not limited to: the Company’s ability to maintain compliance with the NYSE’s continued listing standards; the ultimate proposal by the NYSE and approval by the SEC to make the numeric change to the market capitalization threshold of the continued listing standards permanent; worldwide economic conditions; uncertainties in the credit and capital markets; business conditions in the semiconductor, wireless, precision electronics and other segments of the worldwide electronics industry; competitive factors, including pricing pressures and new products offered by competitors; and the Company’s ability to implement planned cost savings initiatives without adversely affecting the Company’s product development program. Further information on factors that could cause actual results to differ from those anticipated is included in the Company’s annual report on Form 10-K and quarterly reports on Form 10-Q which are filed with the Securities and Exchange Commission. In light of these uncertainties, the inclusion of forward-looking information should not be regarded as a representation by the Company that its plans or objectives will be achieved. Further, the Company is not obligating itself to revise forward-looking statements contained herein to reflect events or circumstances after the date of this release or to reflect the occurrence of unanticipated events.

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 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.