The present invention provides a pressure-sensitive adhesive sheet for protecting a semiconductor wafer, which does not cause curve (warpage) in the semiconductor wafer, when the semiconductor wafer is ground, is excellent in followability to a pattern, has adequate stress dispersibility in a grinding operation, suppresses the crack in a wafer and chipping in a wafer edge, and does not leave a residue of a tackiness agent on the surface of the wafer. The protective sheet has one face having tackiness, does not have an interface existing between a substrate and the tackiness agent and is made of one layer, and the pressure-sensitive adhesive sheet has different tack strengths on both faces from each other.