A semiconductor substrate wafer 2 is supported on a wafer-supporting table 3 so that a surface to be polished is directed upward, a polishing roller 1 is bring to contact with the surface to be polished of the semiconductor substrate wafer 2, and the polishing roller is rolled over the wafer under a pressure whereby a scattering of polishing to the surface of the semiconductor substrate wafer can be eliminated while productivity is increased.