In semiconductor device, a substrate unit includes an insulating substrate, a first conductor substrate and a second conductor substrate which are disposed on one main surface of the insulating substrate and spaced apart from each other, and a third conductor substrate which is disposed on the other main surface opposite to the one main surface of the insulating substrate. A terminal is connected to a surface of a semiconductor element opposite to the first conductor substrate. The terminal extends from a region above the semiconductor element to a region above the second conductor substrate while being connected to the second conductor substrate. At least a part of the terminal, the substrate unit and the semiconductor element is sealed by a resin. The third conductor substrate is exposed from the resin.