PURPOSE: To aim at enhancing the working efficiency, by providing a cutting edge which may be elastically deformed in accordance with the condition of surface of a part of a material to be finished up, to aim at uniformly polishing the surface of the material to be polished, by making the cutting edge adapted to make into contact with a part of the material to be polished, small.

CONSTITUTION: A rotary body 2 is composed of an elastically deformable member such as, for example, a rotary disc 4 formed of a resilient metal plate, and a cutting edge 6 made of ultrahard materials such as diamond chip, carbide chip or the like. Then, a surface polishing device 24 comprises a body 26 and a drive section 28 having a drive shaft 30 attached at its free end with the rotary body 2. Accordingly, during surface polishing work, the cutting edge 6 is moved back and forth in accordance with unevenness of the outer surface of a material to be polished, due to elastic deformation which is caused by a warp, distortion and the like of the rotary disc 4. Further, the polishing work is made such that the rotary body 2 is rotated to grip the body 26 while the drive section 28 is pressed in the direction of the surface of the material 32 to be polished. With this arrangement, the cutting edge 6 may surely reaches any of recesses, thereby it is possible to uniformly polish the material 32.