In a power converter in which semiconductor modules are arranged on both surfaces of a cooler for downsizing, an excellent connection between control boards and a low inductance connection between smoothing capacitors and the semiconductor modules are performed at the same time. The semiconductor modules are disposed on both surfaces of the cooler, and control boards that control the semiconductor modules are arranged opposite to the respective semiconductor modules. The semiconductor modules and the cooler are held between the control boards. A current detector or a terminal block is disposed at a position perpendicular to a surface on which the cooler and the semiconductor modules contact each other, opposite to the cooler. The respective control boards disposed on both surfaces of the cooler are electrically connected by using wirings provided in the current detector or the terminal block.