An object of the present invention is to achieve both low height and miniaturization of a double side cooling type electric power conversion device. A power semiconductor module according to the present invention includes: a circuit body including a power semiconductor device and a terminal; and a case forming an accommodation space for accommodating the circuit body, wherein the case includes: a first heat radiation portion and a second heat radiation portion disposed to face each other sandwiching the accommodation space; a first opening that is disposed at a side portion to the first heat radiation portion and through which the terminal passes; a sealing surface formed to surround the first opening; and a reference surface disposed at a side portion to the second heat radiation portion, and the reference surface is formed on a surface opposite to a surface on which the sealing surface of the case is disposed such that, when projection is performed from a vertical direction of the reference surface, a projection of the reference surface and a projection of the sealing surface overlap each other.