A power control unit (PCU) case accommodates an electric circuit of a PCU, which includes a first capacitor and is operated by electricity supply from a storage battery. In the electric circuit, a first bus bar is connected to a part in the vicinity of the anode of the first capacitor, and a second bus bar is connected to a part in the vicinity of the cathode of the first capacitor. A discharge mechanism is formed by connecting in series a switch activated by an explosive actuator and a discharging resistor. The discharge mechanism is integrally fixed to the PCU case. When a collision of the vehicle is detected, the discharge mechanism short-circuits the first bus bar and the second bus bar with each other through the activation of the switch. Accordingly, the discharge mechanism is connected in parallel with the first capacitor, so that the discharging resistor discharges the first capacitor.