To enable speedily and precisely judging whether it is good or bad by judging whether width of a ring material for a bearing is within an allowable range or not at a ring-width judging part to judge whether deviation of a track groove is within an allowable range or not at a ring track groove judging part.

Two inclined planes being opposed symmetrically to an axis are installed and space between both inclined planes is extended toward an insertion side of a ring material 38 for a bearing. The material 38 is inserted into the space and inspected. Limit scales 36, 37 are installed at positions where a distance between the both inclined planes agrees with a low and a high limit values of a predetermined allowable range of ring width of the material 38. The part is set as a ring-width judging part. A tongue piece 33 formed a radius gauge with predetermined curvature is held by an axis so that it can be advanced and backed on the symmetrical axis of the both inclined planes and a tip point of the piece 33 can be fluctuated, and is fit into a ring track groove when inserting the material 38. A stopper 34 is juxtaposed with the piece 33 to control a fluctuation range of the piece 33 within a predetermined allowable range of deviation in a width direction of the track groove of the material 38. The part is set as a ring track groove judging part.