To provide a grindstone by which rough grinding and finish grinding can be executed by reducing a dead zone and by providing a grinding face for rough grinding and that for finish grinding on the same face.

The grindstone is composed such that the rough grindstone 41, 62 and the finish grinding wheels 42, 63 in a half body, which are obtained by respectively cutting the rough grindstone and the finish grindstone by an inclination line inclined at a prescribed angle to the longitudinal direction, are assembled into a rectangular shape and fixed by bonding. Two grinding faces 64, 65 having different grain sizes are formed with the inclination line 61 as a border.