A semiconductor device includes a semiconductor substrate, and a MOS transistor provided on the semiconductor substrate and having a channel type of a first conductivity, the MOS transistor comprising a semiconductor region of the first conductivity type including first and second channel regions, gate insulating films provided on the first and second channel regions, a gate electrode provided on the gate insulating films, and first and second source/drain regions which are located at a distance from each other so as to sandwich the first and second channel regions, the first and second source/drain regions contacting the semiconductor region of the first conductivity type and forming a Schottky junction.