A semiconductor device which includes a semiconductor chip; an electrically conductive base electrode bonded to the lower surface of the chip by a first bonding member; an electrically conductive lead electrode bonded to the upper surface of the chip by a second bonding member; and a first stress relief member for reducing stress developed in the first bonding member due to the difference in thermal expansion between the chip and the base electrode. Both the base electrode and the first stress relief member are in direct contact with the lower surface of the first bonding member. A protrusion is formed upstanding from the base electrode in direct contact with the first bonding member, and the first stress relief member surrounds a circumferential portion of the protrusion.