To perform finishing polishing with high accuracy by discharging abrasive powder and to prevent the occurrence of uneven polishing.

In a rotary polishing disk, a coarse polishing wheel at the outer peripheral edge and finishing polishing wheel on the inner peripheral side are provided with a gradient of a desired angle to the orthogonal direction of the axis on the same plane. A material to be polished has the surfaces to be polished conformable to the inclinations of the respective wheel surfaces. The polishing disk and the material to be polished are relatively moved with the respective wheel surfaces made conformable to the surfaces to be polished.