A power module includes a power unit equipped with plural power semiconductor devices, heat sinks, and a housing case. The power unit includes the power semiconductor devices, lead frames, and a sealing resin. The lead frames are coupled to the surfaces of each of the power semiconductor devices, and parts of the external surfaces of the upper and lower lead frames are bared out of the sealing resin. The housing case includes a housing base and a housing cover. The housing base, heat sink, power unit, heat sink, and housing cover are layered in that order. Assuming that S1 denotes the outline size of the housing base, S2 denotes the outline size of the housing cover, S3 denotes the size of the lead frame bared part of the power unit, the relationship of S1>S2>S3 is established. The housing cover is pressed and fixed to a receiving part of the housing base.