A semiconductor device includes: a semiconductor chip; a first metal plate disposed on one side of the chip through a first solder layer; a second metal plate disposed on the other side of the chip through a second solder layer; a third metal plate disposed on the second metal plate through a third solder layer; supporting means for holding at least one of distances between the chip and the first metal plate and between the chip and the second metal plate; and excess solder accommodation means for accommodating excess solder in a case where the third solder layer includes the excess solder.