PURPOSE: To make highly accurate form polishing performable even in case of either of soft and hard workpieces without entailing any flaw there, by covering the peripheral surface of a hollowsphere with a coat material having abrasive capacity, while setting up an electronic heating-cooling element and a temperature sensor both inside, and controlling a coat material temperature.

CONSTITUTION: A coat material 32 with abrasive capacity is covered on the peripheral surface of a hollow sphere 31, and an electronic heating-cooling element 33 and a temperature sensor 34 are set up inside, constituting them so as to control a temperature of the coat material 32. And, the hollow sphere 31 is pressed to the surface of a workpiece 16 via the coat material 32, rotating a polishing tool 30, thus it is polished. The polishing is carried out as controlling the temperature of the coat material 32 to be adjusted to an optimum temperature for material and work roughness of the workpiece 16. Therefore, the workpiece 30 is polishable into highly accurate form with a certain polishing tool 30 even in case of either soft and hard workpieces without generating any flaw.