A power semiconductor module capable of reducing variation of inductance between upper/lower arms and reducing variation of current caused by the variation of inductance. The power semiconductor module includes circuit blocks (upper/lower arms) each of which is configured by connecting self-arc-extinguishing type semiconductor elements in series; first and second positive electrode terminals, first and second negative electrode terminals, and first and second AC terminals. Further, there are first and second wiring patterns that connect the self-arc-extinguishing type semiconductor elements to the DC and AC terminals. The outline of the power semiconductor module has a substantially quadrangular surface.