PURPOSE: To uniformalize the distribution of pressure applied on a member to be polished so as to improve the polishing accuracy for a member to be polished by increasing the rigidity of a polishing plate.

CONSTITUTION: A polishing device comprises a polishing plate 1 formed by burying previously burned high rigidity ceramics 1a in a core, wrapping the same with low rigidity ceramics 1b and rubber-pressing the same to be burned, a pressurizing head 2, a pressurizing ring 3, a polishing fluid 4, a polishing fluid pipe 4a, a polishing pad 6 and a polishing board 7. A wafer 5 is uniformly pressurized without flexible deformation in the polishing plate 1 by pressurization of the pressurizing head 2 so as to improve the polishing accuracy of the wafer 5.