A semiconductor device includes: a substrate; an insulator layer provided on the substrate; a first transistor provided on the insulator layer; a semiconductor layer including a plurality of impurity regions of a first conduction type, the impurity regions forming a part of the first transistor; a heat dissipation layer; a thermal conductive layer linking the semiconductor layer and the heat dissipation layer; and an interruption structure configured to interrupt a flow of a current between the first transistor and the thermal conductive layer.