PURPOSE: To efficiently profile a polishing belt to the work curved face by supporting an endless steel belt by a pair of rolls holding smaller roll intervals than that of a pair of the rolls supporting an endless polishing belt.

CONSTITUTION: The curved face of a work W is first abutted to a polishing belt 9 by descending the work W from the upper part of a polishing device. In this case, the polishing belt 9 is largely bent to the lower part because of being easy to bend in the upper and lower directions and brought into contact with a steel belt 8. Since this steel belt 8 is made of steel and supported by the 1st, 2nd rolls 4, 5 having small roll intervals, it is difficult to bend fur. more than the polishing belt 9 and so it pushes back the polishing belt 9. Consequently, the polishing belt 9 is brought into contact comparatively longer with the curved face of the work W and its contact force is held uniformly.