A semiconductor device includes: a gate oxide film formed on a surface of a semiconductor substrate; a gate electrode formed on the gate oxide film; and a high concentration impurity layer connected to a main electrode and formed on the surface of the semiconductor substrate, wherein an impurity species doped in the high concentration impurity layer comprises a first impurity species of phosphorous and a second impurity species of at least one of argon and nitrogen, a concentration of the second impurity species is higher than a concentration of the first impurity species in a surface of the high concentration impurity layer, and a peak position of a concentration distribution of the first impurity species in a depth direction in the high concentration impurity layer is deeper than a peak position of a concentration distribution of the second impurity species in the depth direction.