A semiconductor device includes a first interconnect connected to a high voltage side power supply voltage, a second interconnect connected to the high voltage side power supply voltage, a switching transistor, and a protective element connected in parallel with the switching transistor between the high voltage side power supply voltage and a low voltage side power supply voltage. A first end of the switching transistor is connected to the first interconnect, and a second end is connected to an output terminal. The protective element includes a first p-type semiconductor region connected to the first interconnect, an n-type semiconductor region in contact with the first p-type semiconductor region and connected to the second interconnect, and a second p-type semiconductor region in contact with the n-type semiconductor region, spaced from the first p-type semiconductor region, and connected to the low voltage side power supply voltage.