The present invention provides a substrate-less pressure-sensitive adhesive sheet for protection of semiconductor wafer, which is to be stuck to a front surface of a semiconductor wafer in grinding a back surface of the semiconductor wafer, the pressure-sensitive adhesive sheet consisting of a pressure-sensitive adhesive layer, in which the pressure-sensitive adhesive layer is formed of a UV-curable pressure-sensitive adhesive containing a polymer composed mainly of an acrylic monomer polymerizable compound, the pressure-sensitive adhesive force of a surface of the pressure-sensitive adhesive layer to be stuck to the front surface of the semiconductor wafer is larger than the pressure-sensitive adhesive force of the opposite surface thereof, and the pressure-sensitive adhesive layer has an initial elastic modulus of from 0.01 MPa to 500 MPa.