SEMICONDUCTOR DEVICE

A semiconductor device includes a semiconductor substrate of a first conductivity type; a semiconductor layer located on the semiconductor substrate, the semiconductor layer being of the first conductivity type and including a first device part; a buried layer located between the semiconductor substrate and the first device part, the buried layer being of a second conductivity type; a guard region located at a first-direction side of the first device part, the guard region being of the second conductivity type, a lower end of the guard region contacting the buried layer, an upper end of the guard region reaching an upper surface of the semiconductor layer, the guard region not being located at a second-direction side of the first device part, the second direction being opposite to the first direction; and a first semiconductor region located inside the first device part and being of the second conductivity type.