Abstract: First receiving recesses for receiving distal end portions of slot insertion portions of normal coil segments, and second receiving recesses for receiving distal end portions of long slot insertion portions of variant coil segments are formed at circumferential intervals on outer peripheral surface of an inner twisting jig corresponding to the innermost layer. In a state where the distal end portions of the long slot insertion portions before being twisted are inserted into the second receiving recesses, the first receiving recesses are at positions displaced in the circumferential direction with respect to the distal end portions to be housed therein. Primary twisting is performed by rotating the inner twisting jig in this state, and then the distal end portions of the normal coil segments are inserted into the first receiving recesses and the secondary twisting is performed with a rotational amount larger than that of the primary twisting.