To provide such a polishing device as is able to polish a silicone wafer to the high flatness.

By detecting the displacement of both a block 4 and a surface table 9 by using both an electric micrometer 33 and an eddy current type displacement sensor 34, a controlling means 30 accurately grasps the surface shape of both block 4 and surface table 9 during the polishing work, which exercises great influence over the flatness of the wafer at the completion of the polishing work, and, based on the shape data, the controlling means 30 controls a pressure distribution adjusting mechanism 35, which varies the shape of the block surface, a block pressurizing part 37 and a cooling water (quantity) adjusting mechanism 36 which varies the shape of the surface table, so that the curvature of the surface shape (of both block and flat table) bears the preset relation to each other. In this control, the degree to degradation of a polishing pad 6 is taken into consideration.