Provided is a semiconductor device having excellent heat radiation performance and electromagnetic wave suppression effect. A semiconductor device 1 comprises: a semiconductor element 30 formed on a substrate 50; a conductive shield can 20 having an opening hole 21; a conductive cooling member 40 located above the conductive shield can 20; a heat conductive sheet 10 formed between the semiconductor element 30 and the conductive cooling member 40 at least through the opening hole 21; and a conductive member 11 electrically connecting the conductive shield can 20 and the conductive cooling member 40.