The fuel cell cartridge including: an external casing; a fuel cell body (stack), which is accommodated in the external casing and which includes at least a fuel electrode, an oxidizer electrode, and an ion conductor; and a fuel tank for storing a fuel, wherein the external casing has a penetration hole, which penetrates an inner portion of the external casing and which is in communication with outside air, and wherein an inner wall of the penetration hole is provided with at least an opening communicating with the oxidizer electrode. The fuel cell cartridge is detachably attached to an electric apparatus, and an inlet of the penetration hole of the fuel cell cartridge is situated at a position corresponding to an outside-air communicating port, which is provided in the electric apparatus and which is in communication with outside air.