[LETTERHEAD OF ARTHUR ANDERSEN LLP] Exhibit 23.1 CONSENT OF INDEPENDENT PUBLIC ACCOUNTANTS As independent public accountants, we hereby consent to the incorporation by reference in this Registration Statement on Form S-8 of our report dated February 6, 1998 included in Advanced Energy Industries, Inc.'s Form 10-K for the year ended December 31, 1997. /s/ ARTHUR ANDERSEN LLP Denver, Colorado October 6, 1998