A fuel cell system includes at least one pressure reducing valve connected to a downstream side of a hydrogen gas tank, a hydrogen gas flow path including a first flow path connected to a downstream side of the pressure reducing valve and a plurality of second flow paths connected to a downstream side of the first flow path and branched from the first flow path, a plurality of injector units, each of which is connected to each of the second flow paths, a plurality of fuel cell stacks, each of which is connected to each of the injector units, and a control unit controlling opening and closing of the injector units. The control unit sets valve closing periods of the injector units to periods deviating from each other such that at least one of the injector units is always opened when the fuel cell system satisfies a predetermined operating condition.