A power distributor having: a bus bar aggregation B made out of a single plate material; semiconductor switching devices 14 mounted on the bus bar aggregation B; and a housing 22 made out of an electrical insulating material such as resin or the like and molded around the device-containing bus bar aggregation B. Amethod of manufacturing the power distributor is constituted by the steps of: forming the bus bar aggregation B; molding the housing 22 around the bus bar aggregation B after the semiconductor switching devices 14 are mounted on the bus bar aggregation B; and completing a power distribution circuit after cutting off suitable portions of the bus bar aggregation B after the molding.