A polishing method where a semiconductor wafer (W) is held by a top ring (23), pressed against a polishing surface (10) and polished. An elastic diaphragm (60) is installed on the lower face of an vertical moving member (62) so as to define a pressure chamber (70) in the top ring (23). A pressurized fluid is supplied to the pressure chamber (70) in order that the semiconductor wafer (W) is pressed against the polishing surface (10) by the fluid pressure of the fluid and polished. The pressurized fluid is jetted from an opening (62a) formed at the center of the vertical moving member (62) in order to separate the polished semiconductor wafer (W) from the top ring (23).
