Abstract: According to one embodiment, in a method, while supporting as end of an extension part of a coil segment by a flange of a forming jig from the radially outside and pressing an inclined, surface toward the other end surface in an axial direction of the stator core by a pressing part of the forming jig, rotating the stator core in a circumferential direction relative to the forming jig, in order to bend the extension part in the circumferential direction of the stator core such that the inclined surface is positioned to be substantially parallel to the other end surface. Thereafter, joining the inclined surfaces adjacent to each other is the radial direction of the stator core.