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Advanced Energy and Symphony Systems Establish Key Strategic Alliance with Yokagawa Electric Corporation

FORT COLLINS, Colo. and CAMPBELL, Calif. (July 16, 2001)—Advanced Energy Industries, Inc. (Nasdaq: AEIS), Symphony Systems and Tokyo-based Yokogawa Electric Corporation announced today the establishment of a key strategic alliance designed to strengthen the position of all three companies in the equipment engineering system (EES) market for improving equipment productivity.

In this new relationship Yokogawa will market its product, e-fabDoctor EPM, a tool for improving the productivity of equipment used in the manufacture of semiconductor devices by gathering, analyzing and controlling equipment performance data. This product will incorporate EES technology developed by Symphony Systems and distributed to the semiconductor market exclusively by Advanced Energy (AE) under a strategic partnership established in March 2000. Specifically, e-fabDoctor EPM incorporates Symphony’s open architecture and external equipment server (eSES), as well as other Symphony products to provide software connectivity.

Bill Shade, product director of Convergent Technologies for Advanced Energy, stated, “This is an ideal combination of strengths, with Yokogawa’s strong presence in fab automation, AE’s capability with process tool subsystems and Symphony’s strength in connecting the two together. With overall equipment effectiveness (OEE) running at around 50 percent, device manufacturers see the improvement of equipment productivity as one of the highest leverage areas for cost reduction. The e-fabDoctor EPM, with its e-Diagnostics capability, can greatly improve equipment productivity.”

“The EES products offered by Advanced Energy and Symphony Systems, which enable fab engineers and operators to access and share tool and sensor data, provide critical software connectivity to our e-fabDoctor EPM tool,” said Yoichi Kato, product marketing manager of the Semiconductors Solution Center for Yokogawa Electric Corporation. “This joint effort will leverage our infrastructure in the Japanese and Asian market, and the strengths of Advanced Energy and Symphony Systems in regions outside of Japan will allow us to expand our worldwide market opportunity and bring expanded equipment monitoring capabilities to our customers.”

Yokogawa will also have non-exclusive rights to distribute Symphony's stand-alone products in Japan.

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.

About Symphony Systems
Founded in 1997, Symphony uses its network-based tool connectivity infrastructure and suite of software applications to seamlessly connect people with new and existing equipment within an entire supply chain, allowing equipment users, equipment suppliers, parts and consumables suppliers, and application software providers, to collaborate to improve equipment productivity through real-time equipment interaction. More information can be found on www.symphony-systems.com.

About Yokogawa Electric Corporation
Yokogawa's global network of 18 manufacturing facilities, 71 affiliate companies and over 200 sales and engineering offices span 28 countries. Since its founding in 1915, the US$3 billion company has been engaged in research and innovation of the highest order, securing over 4,500 patents and registrations, including the world's first DCS and digital flow and pressure measurement sensor. Test and measurement systems are a core business focus of Yokogawa. For more information about Yokogawa Electric Corporation, please visit the corporate website at www.yokogawa.com.

Safe Harbor Statement
This press release contains 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: the volatility and cyclicality of the semiconductor and semiconductor capital equipment industries, the company's ongoing ability to develop new products in a highly competitive industry characterized by increasingly rapid technological changes, the possibility of unanticipated manufacturing and marketing costs associated with meeting the demands of the new relationship with Yokogawa Electronics Corporation, the company's ability to maintain an ongoing partnership with Symphony Systems, and other risks described in Advanced Energy's Form 10-K, Forms 10-Q and other reports and statements, as filed with the Securities and Exchange Commission. These reports and statements are available on the SEC's website at www.sec.gov. Copies may also be obtained by contacting Advanced Energy's investor relations at 970.407.6732. The company assumes no obligation to update the information contained in this press release.