To improve machining efficiency by providing work holding means holding and rotating disk-like works having chamfered outer peripheral edges on the surface and the back face and bringing the edges of the works into contact with multiple polishing drums simultaneously.

Three work holding means 12 are radially arranged at intervals of 120° to surround the periphery of three polishing drums 11 on a rotary table 10 so that each work holding means 12 is located just in the middle between two adjacent polishing drums 11. Each work holding means 12 holds a disk-like work 1 having outer peripheral edges 1a, 1b chamfered at the angle θ on the surface and the back face, rotates it around the axis, and brings the outer peripheral edges 1a, 1b of the work 1 into contact with the work faces of two adjacent polishing drums 11 simultaneously.