To provide a semiconductor device less affected by noise without making a manufacturing process more complicated and increasing a chip area. The device has a semiconductor substrate having first and second surfaces, a first-conductivity-type drain region on the second surface side in the semiconductor substrate, a first-conductivity-type drift region on the first surface side of a substrate region, a second-conductivity-type base region on the first surface side of the drift region, a first-conductivity-type source region on the first surface of the semiconductor substrate sandwiching a base region between the source and drift regions, a gate electrode opposite to and insulated from the base region, a wiring on the first main surface electrically coupled to the source region, and a first conductive film on the first main surface, opposite to and insulated from the wiring, and electrically coupled to the substrate region.