One problem to be addressed has been the inability to cut off electric current because, depending on the impedance in a path, an electric current interruption element would not be fused even when a voltage breakdown element is brought into conduction. Thus, inductor elements 730 for preventing noise are provided between a voltage breakdown element 720 and a power supply circuit 800 to be protected. With this configuration, it becomes possible to protect the power supply circuit 800 to be protected, by attenuating the impact of a frequency component f generated in the course of bringing the voltage breakdown element 720 into conduction so as to assuredly fuse the current interruption element 710. Further, it becomes possible to prevent noise by providing an EMC measure by the inductor elements 730.