PURPOSE: To perform polishing with no unevenness in a short time, by providing both end surfaces of a drum tilting with respect to a main spindle so as to allow chips to flow in a circumferential direction and an axial center direction.

CONSTITUTION: Both end surfaces 2 are mounted to be stopped to main spindles 3, 3 having a fixed tilt angle θ with respect to the center axis Z-Z of a drum. If the drum of such constitution rotates, the drum, generating unbalance in a part corresponding to ABC, DEFT, is balanced by weights 5, 6. Because of this constitution, rotation of the drum causes chips and polished materials to generate a flow by their movement in the axial direction in addition to the flow along the circumferential direction. According, the chips and the polished materials can perform polishing providing a predetermined glossy surface in a short time, while the chips and the polished materials, uniformly mixing with each other, enables the polishing with no unevenness to be performed.