A low cost, small scale semiconductor device including a trimming circuit having a fuse resistor is disclosed. By a trimming circuit being configured of a MOSFET, a protection circuit, and a fuse resistor, it is possible to carry out a change from an open circuit state to a short circuit state by fusing the fuse resistor. Also, by the protection circuit and fuse resistor configuring the trimming circuit being formed in a two layer structure, it is possible to reduce the size of the trimming circuit, and thus it is possible to provide a low cost, small scale semiconductor device having a trimming circuit that occupies a small area.