Upon grinding a back of a substrate, a protecting tape made of a material soluble to IPA (isopropanol), for example, a vinyl acetate thermoplastic adhesive is appended on the surface of a pattern-formed layer of a wafer, grinding the back, dipping the wafer in a cleaning vessel containing IPA, and dissolving and removing the protecting tape from the wafer, thereby giving no damages to the wafer, and reducing the number of operation steps.