PURPOSE: To provide the concentrated polishing action under the point or line contact condition by urging a projection arcuate urging body of a polishing table against a cam surface to lap the cam surface with the rotation of a cam shaft and the reciprocation of the polishing table.

CONSTITUTION: A cam shaft 1 is supported by both centers and rotated by driving a spindle, while a slide table 11 is reciprocated. Then, since a polishing table 27 is pressed against a cam surface 2 of the cam shaft 1 by a spring 24, lapping is carried out by the composite motion of the circumferential motion of the cam surface 2 due to the rotation of the cam surface 2 and the widthwise motion of the polishing table 27 due to the lateral motion of the slide table 11. And since the polishing table 27 has a projection arcuate portion along an urging body 22, it makes point or line contact with the cam surface 2 to polish effectively projections remaining on the cam surface 2.