An electric power converter includes a semiconductor module with a built-in switching element, a cooler that cools the semiconductor module, and a metallic case provided with an internal space that accommodates the semiconductor module and the cooler. The case is formed by combining a first case member and a second case member. The case includes an outer fixing portion for connecting and fixing the first case member and the second case member on an outside of the internal space, an inner fixing portion for connecting and fixing the first case member and the second case member on an inside of the internal space. The case includes a partition wall that is formed continuously from the inner fixing portion and partitions the internal space. A heat-generating component disposed along a wall surface of the partition wall is accommodated in the internal space.