For more information, contact:

Richard Beck Advanced Energy Industries, Inc. 970.407.6204 dick.beck@aei.com

Cathy Kawakami Advanced Energy Industries, Inc. 970.407.6732 cathy.kawakami@aei.com

Fort Collins, Colorado (May 10, 2001)—Advanced Energy Industries, Inc. (Nasdaq: AEIS) today announced revisions to the second quarter outlook. Advanced Energy is an industry-leading provider of critical technology solutions for the manufacture of semiconductors, data storage products, and flat panel displays.

"We are operating in an extremely volatile environment of limited visibility, low order volumes and order cancellations," said Doug Schatz, chairman and chief executive officer. "Given the sales and order activity to date, we have revised our expectations for the 2001 second quarter."

"We now expect second quarter revenues to be lower than our 2001 first quarter revenues of $74.7 million by as much as 35 percent. Although we have taken aggressive action to reduce costs in the past few months, this lower revenue base does not support our model for profitability in the second quarter," said Mr. Schatz.

The company will explore further cost reduction actions as appropriate, and in relation to the continued evaluation of revenue forecasts and order trends. Advanced Energy will report second quarter results on Thursday, July 12, 2001. Conference Call Management will host a conference call today, May 10, 2001 at 10:00 am Eastern time to discuss this press release. You may access this conference call by dialing 888-792-1079. For a replay of this teleconference, please call 703-925- 2533, passcode 5231251. The replay will be available through Thursday, May 17, 2001. There will also be a webcast available at www.advanced-energy.com in the "Investor Relations" section.

About Advanced Energy
Advanced Energy is a global leader in the development, marketing, and support of technology solutions that are central in the manufacture of semiconductors, data storage products, and flat panel displays. Original equipment manufacturers (OEMs) and end-users around the world depend on AE products when plasma-based technology plays a vital role in their manufacturing process. AE offers a comprehensive suite of products for vacuum process systems, including power management, temperature sensing, dynamic temperature control, gas delivery management, process monitoring and machine control tools, ion-beam sources, and plasma abatement technologies. AE technology solutions are sold and supported globally by direct offices, representatives, and distributors. Founded in 1981, AE is a publicly held company traded on Nasdaq under the symbol AEIS. AE's URL is www.advanced-energy.com

Safe Harbor Statement
This press release contains certain forward-looking statements subject to known and unknown risks and uncertainties that could cause actual results to differ materially from those expressed or implied by such statements. Such risks and uncertainties include, but are not limited to: fluctuations in quarterly and annual revenues and operating results, Advanced Energy’s ongoing ability to develop new products in a highly competitive industry characterized by increasingly rapid technological changes, the volatility and cyclicality of the semiconductor and semiconductor capital equipment industries and other risks described in Advanced Energy’s 10-K, Forms 10-Q and other reports and statements, as filed with the Securities and Exchange Commission. The company assumes no obligation to update the information in this press release.