PURPOSE: To provide a method of polishing a semiconductor wafer which can separate the semiconductor wafer from an upper surface table and retain the semiconductor on a lower surface table when the upper surface table is lifted in double-side polishing.

CONSTITUTION: The contact area of an upper surface plate 3 and a semiconductor wafer 1 is set smaller than that of a lower surface table 5 and the semiconductor wafer 1. When the upper surface 3 is lifted up, the semiconductor wafer 1 is stayed on the lower surface table 5 side to be surely separated from an emery cloth 2 on the upper surface wafer 3.