EX-23.1 6 c86449a1exv23w1.txt CONSENT OF ERNST & YOUNG LLP EXHIBIT 23.1 CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM We consent to the reference to our firm under the caption "Experts" and to the use of our reports dated June 8, 2004, in Amendment No. 1 to the Registration Statement on Form S-1 (No. 333-117274) and related Prospectus of Eagle Test Systems, Inc. filed with the Securities and Exchange Commission on or about August 12, 2004. Chicago, Illinois /s/ ERNST & YOUNG LLP August 12, 2004