To form a desired edge of a shell plate of a rear pillar spreading to a triangular shape continuing to an upper part of a specified width and the lower side thereof as a beading by hemming.

A workpiece is pressed by a die and punch having desired step parts to form a step part along the edge of the workpiece. The workpiece with the step part formed is bent to be raised on an inner side from a site for forming the step part and the side inner than the raised site of the raise work is held between both sides of pressing members; in addition, the edge side is pressed while held between both sides of pressing members provided with pressing surfaces similar to the step part, thereby the portion on the edge side is fallen at an acute angle toward the portion on the inner side. The portion nearer the edge side than the step part of the work fallen at the acute angle is pressed to an opposite workpiece surface and the portion between the step part and the raised area is pressed toward the workpiece surface in such a manner that the spacing from the workpiece surface is maintained.