A method of manufacturing a commutator main body which has a cylindrical insulating body, and a plurality of segments arranged in an outer circumference of the insulating body. A short-circuit member is arranged in an end in an axial direction of the insulating body. The short-circuit member has a plurality of first short-circuit pieces and a plurality of second short-circuit pieces. A tabular insulating portion covers first coupling portions of the first short-circuit pieces, and second coupling portions of the second short-circuit pieces. The insulating portion has a restriction recess, and the end in the axial direction has a restriction projection. The restriction projection is engaged with the restriction recess, whereby the movement of the short-circuit member in the circumferential direction with respect to the commutator main body is restricted. Accordingly, the assembly of the short-circuit member in the commutator main body is facilitated.