To stably rotate a grinding head without movement by locating a center of gravity of a band-shaped grinding film supplying means and a center of gravity of a band-shaped grinding film collecting means on a rotation axis of the grinding head.

A grinding film supplying means 9 is capable of feeding a grinding film 8 along an elastic pad 7 which is detachably provided on a grinding surface of a grinding head 4. A grinding film collecting means 10 is capable of winding and collecting the grinding film 8 that the grinding film supplying means 9 supplies to the grinding surface of the grinding head 4. Each center of gravity of both of the grinding film supplying means 9 and the collecting means 10 is arranged so as to be located on a rotation axis 20 of the grinding head 4. As a result, the grinding head 4 is capable of stably rotating without moving, even if the grinding head 4 rotates. Even if each gravity of the grinding film supplying means 9 to the collecting means 10 holding the grinding pad 8 is not the same, the grinding head 4 does not move.