In a semiconductor device, a second heat sink and a third heat sink are electrically connected by a joint portion in an alignment direction in which a first switching element and a second switching element are aligned. A second power-supply terminal is disposed in the alignment direction in a region between a first power-supply terminal and an output terminal and between the second heat sink and the third heat sink. In an encapsulation resin body, at least one of a shortest distance between a first potential portion at same potential as the first power-supply terminal and a third potential portion at same potential as the output terminal and a shortest distance between a second potential portion at same potential as the second power-supply terminal and the third potential portion is shorter than a shortest distance between the first potential portion and the second potential portion.