EXHIBIT 23 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the incorporation by reference in Registration Statement File Nos. 333-108076, 333-109963, 33-62967, 33-62971, 333-32394, 333-68059, 333-37913, 333-55764, 333-86410, and 333-106335 of Norstan, Inc. on Form S-8(3) of our report dated July 22, 2004, appearing in this Annual Report on Form 10-K of Norstan, Inc. for the year ended April 30, 2004. DELOITTE & TOUCHE LLP Minneapolis, Minnesota July 27, 2004