Provided is a semiconductor device having excellent heat dissipation capacity and electromagnetic wave suppression effect. A semiconductor device 1 includes a semiconductor device 30; a tubular conductive shield can 20 provided to surround a side surface 30a of the semiconductor device 30; a conductive cooling member 40; and a conductive thermally conductive sheet 10 formed between the semiconductor device 30 and the cooling member 40. The conductive shield can 20 and the cooling member 40 are electrically connected through the conductive thermally conductive sheet 10 therebetween.