In a semiconductor device, a semiconductor substrate includes a bulk layer, a buried oxide layer provided in at least a partial region on the bulk layer, and a surface single crystal layer on the buried oxide layer. An inductor is provided above a main surface side of the semiconductor substrate on which the surface single crystal layer is disposed. To increase a Q value of the inductor, a ground shield is an impurity region formed in the bulk layer below the inductor and below the buried oxide layer.