A semiconductor device includes two semiconductor chips that are interposed between a pair of radiation members, and thermally and electrically connected to the radiation members. One of the radiation members has two protruding portions and front ends of the protruding portions are connected to principal electrodes of the semiconductor chips. The radiation members are made of a metallic material containing Cu or Al as a main component. The semiconductor chips and the radiation members are sealed with resin with externally exposed radiation surfaces.