To provide a chamfering method of a wafer with an orientation flat, not causing the sectional shape of a chamfering part to vary in each of the outer peripheral part, orientation flat straight part and orientation flat corner rounded part of the wafer to obtain a favorable chamfering shape.

Between the straight part and the corner rounded part of the orientation flat, at least one part is chamfered with a grinding wheel groove different from a grinding wheel groove for chamfering the outer peripheral part of the wafer W, and chamfering is performed by grinding wheel grooves of shapes suitable for the outer peripheral part, the orientation flat straight part and the orientation flat corner rounded part of the wafer W, respectively, whereby even when chamfering is performed with the rotating shaft of the grinding wheel inclined at a designated angle in the tangential direction to the outer periphery of the wafer to obtain favorable surface roughness, the sectional shapes of the respective parts are not varied.