A semiconductor device includes a circuit-to-be-adjusted in which an output characteristic thereof can be adjusted by a fuse that is controlled based on a fuse signal. The semiconductor device includes a control circuit using, as a power source, an internal power source that has a converted voltage obtained by converting a voltage of an external power source, the control circuit being configured to generate control signals A, B based on an inputted test signal, the control signals being able to adjust the circuit-to-be-adjusted in place of the fuse signal. The semiconductor device includes a selector circuit that selects the fuse signal before the internal power source reaches a stable state after the external power source is turned on, and selects the control signal CS after the internal power source has reached a stable state.