Provided is a technology capable of improving a production yield of a semiconductor device having, for example, IGBG as a semiconductor element. After formation of an interconnect on the surface side of a semiconductor substrate, a supporting substrate covering the interconnect is bonded onto the interconnect. Then, a BG tape is overlapped and bonded onto the supporting substrate and the semiconductor substrate is ground from the backside. The BG tape is then peeled off and an impurity is introduced into the backside of the semiconductor substrate by ion implantation. Then, the supporting substrate is peeled off, followed by heat treatment of the semiconductor substrate.