A method of manufacturing a molded commutator for a vacuum cleaner motor, includes providing a cylindrical molding ring; arranging commutator segments in a circle along an inner periphery of the cylindrical molding ring such that grooves are formed between adjacent pairs of the commutator segments and the grooves are extended orthogonal to the rotating direction; press-fitting cylindrical varistors between the commutator segments, with a press-fitting load for each of the varistors ranging from 2 kN to 5 kN; and resin-molding the commutator segments and the varistors together with a molding material so as to maintain integral engagement of the commutator segments and the varistors; wherein the commutator segments are of copper alloy containing silver, and the varistors are of zinc oxide compounds; wherein side surfaces of the varistors contact with the adjacent pairs of commutator segments; and flexible metal is printed on the contacting side surfaces of the varistors.