An electromagnetic main stop valve which is opened by an electromagnetic force of a solenoid with energization of a valve body in a valve-closing direction by energizing unit is provided in a hydrogen tank. A current sensor and the accelerator opening-degree sensor for detecting a use gas flow rate in a fuel cell stack are provided. A pressure sensor for detecting a pressure in the hydrogen tank is provided. The control device sequentially sets the electromagnetic force of the solenoid so that a valve-opening amount is such an amount as to supply a use gas flow rate to the fuel cell stack based on detection values of the current sensor or the accelerator opening-degree sensor, and the pressure sensor. When the flow rate of hydrogen gas flowing into a gas supply path increases due to a hydrogen gas leak, the main stop valve is automatically closed.