To reduce the width of an imperfect stuck part by oxidizing a stuck silicon wafer in the wet atmosphere of a specified intra-furnace temperature and chamfering the outer peripheral part of a wafer for active layer to the inner side of the direction of a wafer radius.

Silicon single crystal is block-cut and mechanochemical grinding is executed on the crystal and the wafer 1 for active layer and a wafer 2 for supporting substrate are obtained. The wafer 1 for active layer and the wafer 2 for supporting substrate are stuck at the room temperature of a clean room. It is inserted into the quartz reaction tube of a heating furnace and an oxidation processing is executed at the wet atmosphere of the intra-furnace temperature 1,000°C-1,200°C. Next, the imperfect stuck part at the outer peripheral part of the active wafer 1 is chamfered to the width of not more than 1mm. Only the imperfect stuck part 1a of the wafer 1 for active layer, which needs chamfering, in the wafer 1 for active layer and the wafer 2 for supporting substrate can be chamfered.