For more information, contact:

Joe Monkowski Advanced Energy Industries, Inc. 970.407.6252

Marna Shillman Advanced Energy Industries, Inc. 970.407.6280 marna.shillman@aei.com

MARCH 23, 1999 — Advanced Energy Industries, Inc. (AE), has been named the recipient of the Outstanding Service Award by Novellus Systems, Inc.’s PVD products group (part of the Metals Division) in San Jose, Calif. AE received the award for “contributions and dedicated service to Novellus Systems for 1998”. The award was announced at Novellus’ Supplier Appreciation Day held in February. Novellus is a leading manufacturer of semiconductor fabrication systems and holds this event annually to recognize suppliers who deliver excellent quality, delivery, and value.

Novellus PVD Purchasing Manager Tim Sandford noted that, “Novellus strives to offer our customers the finest equipment and services available, and having excellent suppliers is a big part of the equation. AE has demonstrated a commitment to quality service that’s above the crowd.”

Frank Canonico, AE’s Novellus Account Manager, said,” Providing top-notch service to Novellus is an on-going team effort. AE coordinates among its New Jersey, Colorado, and California offices to give Novellus—and all of our customers—great service. Joe Monkowski, AE’s senior vice president for sales and marketing, commented, “Meeting and exceeding customer expectations is part of AE’s mission. It’s gratifying to have Novellus recognize our efforts.”

Advanced Energy Industries, Inc., is a leading developer and manufacturer of power supplies and related products that are critical in the manufacturing of semiconductors, data storage devices, flat panel computer displays, and other products using thin-film technology. Founded in 1981, AE is a publicly held company. Its stock is traded under the Nasdaq symbol AEIS. The Web site address is www.advanced-energy.com.