The object is to provide a technology for enabling detection of the voltage resistance in an assembled snubber substrate. A semiconductor device includes: a snubber substrate fixed to a base while being spaced from a p electrode and an n electrode; a snubber circuit disposed on the snubber substrate and electrically connected to the p electrode and the n electrode; and a semiconductor element electrically connected to the snubber circuit. The base includes an insulating component insulating the p electrode, the n electrode, and the snubber substrate from one another.