EXHIBIT 99.1 Consent of Ernst & Young LLP, Independent Auditors We consent to the inclusion in the Form 8-K/A of Mettler-Toledo International, Inc. of our report dated February 2, 2001 with respect to the financial statements of Rainin Instrument Company, Inc. for the year ended December 31, 2000. /s/ Ernst & Young LLP Boston, Massachusetts December 20, 2001