There is provided a Schottky barrier diode wherein concentration of an electrical field at an edge of an insulation layer is suppressed to improve the reverse breakdown voltage. An n<-> layer of a compound semiconductor substrate constituted by an n<+> layer and the n<-> layer is configured in the form of a mesa. An insulation layer is formed on at least a skirt portion and a slant portion of the mesa. An anode is formed on the insulation layer and n<-> layer, and a cathode is formed on the n<+> layer. Thus, concentration of an electrical field at an edge of the insulation layer is canceled by an electrical field generated at the anode on the slant portion to improve the reverse breakdown voltage. <IMAGE>
