Abstract: A semiconductor device according to an embodiment includes: an insulating film formed on a voltage supporting region B; an overvoltage protection diode that includes an n-type semiconductor layer and a p-type semiconductor layer; conductor portions that are formed on the insulating film and are electrically connected to the overvoltage protection diode; and a high-potential portion arranged above the overvoltage protection diode via an insulating film. The p-type impurity concentration of the p-type semiconductor layer is lower than the n-type impurity concentration of the n-type semiconductor layer. In the reverse bias application state, the high-potential portion has a higher potential than a potential of the potential of the p-type semiconductor layer disposed directly under the high-potential portion.