A semiconductor device improves a Schottky-barrier field-effect transistor. In a semiconductor device including a gate electrode formed with interposition of a gate insulating film on a channel formed on a semiconductor substrate, and a Schottky source/drain formed within a top surface of the substrate to be positioned on both sides of the gate insulating film so that end portions of the Schottky source and the Schottky drain do not cover a lower end portion of the gate insulating film and so as to form Schottky junctions with the semiconductor substrate, a Schottky barrier height at an interface between the end portion of the Schottky source and the semiconductor substrate and a Schottky barrier height at an interface between the end portion of the Schottky drain and the semiconductor substrate are different from Schottky barrier heights at interfaces between portions except the end portions of the Schottky source/drain and the substrate.