A fuel cell is provided to enable spontaneous feed of oxygen by using no oxygen in the air, thereby avoiding a need for an additional oxygen supplying device and fuel pump and improving the reaction efficiency. A fuel cell comprises: a fuel cell stack(50); an oxygen tank(10) communicated with the cathode(51) of the fuel cell stack and storing oxygen therein; and an oxygen valve(20) interposed between the cathode and the oxygen tank and controlling the oxygen feed from the oxygen tank to the cathode. The oxygen tank and the oxygen valve are designed in the form of a cartridge capable of filling oxygen to the oxygen tank separately.
