A conventional layout of power supply protective element cannot sufficiently protect an internal circuit against a surge current that flows into a narrow branch line that branches off from a thick main wiring line. A semiconductor device according to an embodiment of the present invention includes a power supply protective element connected around a terminal; a main wiring line connected with a VCC pad or a GND pad; a branch line that branches off from the main wiring line and applies a power supply potential or a ground potential to a functional block of the semiconductor device; a branching portion at which the branch line branches off from the main wiring line; and an internal power supply protective element connected with the branch line.