A BGA type semiconductor device includes: a substrate having wirings and electrodes; a semiconductor element disposed on the substrate, having a rectangular plan shape, and a plurality of electrodes disposed along each side of the semiconductor element; a plurality of wires connecting the electrodes on the semiconductor element with the electrodes on the substrate; a heat dissipation member disposed on the substrate, covering the semiconductor element, and having openings formed in areas facing apex portions of the plurality of wires connected to the electrodes formed along each side of the semiconductor element; and a sealing resin member for covering and sealing the semiconductor element and heat dissipation member.