A fuel cell circuit of a fuel cell system includes a fuel cell unit having an input on the anode side for feeding fuel from a storage tank to the fuel cell unit, and an output on the anode side for discharging fuel cell waste gas on the anode side from the fuel cell unit. A recirculation circuit is provided, to return the fuel cell waste gas on the anode side to the input on the anode side. The recirculation circuit is connected to an intake line of an ejector unit, and fuel can be fed from the storage tank directly into the recirculation circuit.