PURPOSE:To stabilize minute pressuring force of a polishing tool to a work surface, by installing an air outlet between a hydrostatic bearing, supporting a shaftlike rotor to which the tool is tightly attached, and a pressure cylinder, in case of an optical mirror polisher or the like. CONSTITUTION:A rotary part consisting of a polishing tool 40, a shaft 42, a rotor 44 and a rotor magnet 46, and a fixed part consisting of a cylinder 48 and a coil 50 both are made entirely rotated in noncontact and shiftable up and down by a fluid out of pads 62a and 62b or the hydrostatic bearing installed in the cylinder 48, for example, air pressure. And, if the air pressure is properly led into both sides of the rotor 44 from both lower and upper pressurized air inflow ports 52 and 56, the polishing tool 40 is added with the specified pressuring force. Here, since air outlets 64a-64c are installed between cylinder chambers 54, 58 and these pads 62a and 62b, respectively, no influence is exerted on each pressuring force. Thus, minute pressurizing force of the polishing tool against the work surface is stabilized, so that a highly accurate polishing surface is attainable.