The present invention includes: a plurality of semiconductor modules on a metal base (conductor base); a first insulating bus bar and a second insulating bus bar connecting the semiconductor modules; a box-like insulating resin frame around the semiconductor modules; a first insulating layer that seals the semiconductor modules, the first insulating layer having an upper surface at a position that is lower than upper ends of terminals extending from an insulating circuit substrate of the semiconductor module inside the insulating resin frame; and second insulating layers on the first insulating layer inside the insulating resin frame, the upper ends of the terminals being buried inside the second insulating layers. Interfaces formed by the first insulating layer, second insulating layers, and sidewall parts (third insulating layer) of the insulating resin frame are arranged between the terminals and ground positions formed at the lower ends of the sidewall parts.