An ECU of a fuel cell system supplies cathode gas by rotating an air pump at a low-load rotational speed and performs a low-load power generation in a fuel cell stack, while a moving body is traveling. When the fuel cell stack generates power while the moving body is stopped, the ECU increases the supply amount of the cathode gas by rotating the air pump at a during-stoppage-of-traveling rotational speed which is greater than the low-load rotational speed.