To make it possible to efficiently manufacture a ring-like member with high circularity.

An intermediate molding 2 where a belt-like metallic material is bent into a circular shape and its end parts are mutually superposed by a prescribed dimension. The intermediate molding 2 is formed into a perfect circle with a curvature radius that a finished product is to have. The molding 2 is set in a butt welding machine and held between a pair of electrode parts which is deviated in a height direction. Thereafter, the molding 2 is spread out without the occurrence of positional deviation, its end parts are abutted on each other, and the molding 2 is energized. The portion held between the electrode parts maintains its initial curvature radius as it is. The remaining portion has again the initial curvature radius after jointing since the dimension of the superposed portion is the same as that for its fusion margin portion, so that the obtained product has a high circularity.