The present invention provides a cleaning substrate of a substrate processing equipment, which comprises a cleaning layer comprising a heat resistant resin with a storage modulus (1 Hz) at 20.degree. C. up to 150.degree. C. being 5.times.10.sup.7 Pa to 1.times.10.sup.9 Pa on at least one face of the substrate; and a polyimide resin suitable as the heat resistant resin for the cleaning layer and usable under circumstances possibly involving the generation of serious disadvantages due to silicone contamination, such as for HDD application and some semiconductor applications.