A power semiconductor device includes: a substrate in which a positive electrode wiring connected to a first conductor on a high potential side and a negative electrode wiring connected to a fourth conductor on a low potential side are provided on one surface, and an output wiring connected to a second conductor and a third conductor is provided on the other surface so as to face the positive electrode wiring and the negative electrode wiring; and a first capacitor that smooths DC power supplied to a first upper-arm circuit body and a first lower-arm circuit body. The substrate is disposed between the first upper-arm circuit body and the first lower-arm circuit body. The first capacitor is disposed between the first upper-arm circuit body and the first lower-arm circuit body, and is connected to the positive electrode wiring and the negative electrode wiring on the substrate.