A power semiconductor module is equipped with: a frame made of an insulator; a first electrode plate made of a metal and fixed to a bottom opening of the frame; semiconductor chips electrically and physically connected to the first electrode plate; a multilayer substrate fixed to a principal surface of the first electrode plate; wiring members that electrically connect front surface electrodes of the semiconductor chips and a circuit plate of the multilayer substrate; a second electrode plate fixed to a top opening of the frame; and a metal block that has a first surface having a projected portion and a second surface disposed on a side opposite to the first surface and that is tapered from the first surface to the second surface, the projected portion being electrically and physically connected to the circuit plate of the multilayer substrate and the second surface being electrically and physically connected to the second electrode plate.