Abstract: A semiconductor device 100 is configured as having a semiconductor substrate 102 having a first-conductivity-type semiconductor region 104 formed in its surficial portion; an anode 146 of a Schottky barrier diode formed on the first-conductivity-type semiconductor region 104; a second-conductivity-type guard ring 114 formed along the periphery of the anode 146 in the surficial portion of the first-conductivity-type semiconductor region; an isolation insulating film 108 formed along the periphery of, and being spaced from, the guard ring 114 in the surficial portion of the first-conductivity-type semiconductor region 104, so as to isolate the anode 146 from the other regions; and an anode-forming mask 110a covering the surface of the semiconductor substrate in a portion fallen between the anode 146 and the isolation insulating film 108, and being in contact with the end portion of the anode 146.