PURPOSE: To make a work position for a work constant and to increase working accuracy by radially fitting plural flexible plate like members to the outer peripheral part of a wheel to be driven by rotating and arranging freely movably an endless sandpaper covering the plate like member.

CONSTITUTION: When a polishing device 20 is driven by rotating and a wheel is rotated in an arrow mark direction, each sandpaper 10 is pressed to a rotating shaft 17 by centrifugal force. Then, due to each rotating shaft 17 being rotated each sandpaper 10 whose one end is wound on the rotating shaft 17 is forcibly rotated in an arrow mark direction. In case of performing polishing work in this state, the cutting force in the same degrees as that obtd. by a belt sander with having the flexibility more than a flap wheel is obtd. by the compound effect of the pressing force of a sandpaper 10 caused by the rotation of the wheel and the cutting force caused by the rotation of the sandpaper 10 itself.