A semiconductor module includes an insulating substrate (200) that is made of AlN and that has a first plane (201) and a second plane (202) both of which face mutually opposite directions, a first conductor layer (210) formed on the first plane (201), a second conductor layer (220) formed on the second plane (202), a semiconductor device (300) bonded to the first conductor layer (210) with a first solder layer (510) interposed therebetween, and a heat dissipation plate (400) that is formed in a rectangular shape when viewed planarly and that is bonded to the second conductor layer (220) with a second solder layer (520) interposed therebetween, and, in this semiconductor module, the heat dissipation plate (400) is deformed so as to become convex in a direction in which the second plane (202) is pointed when viewed from a width direction thereof.