High-efficiency fuel cell system as the beam teoming fuel cell assembly including a topping cathode portion and stopping a fuel cell assembly comprising a topping anode portions, beams teoming cathode portion and the beam teoming anode portions, beams teoming anode part is discharged from the topping anode portions comprising the anode exhaust to receive the said beam teoming fuel cell assembly, and a carbon dioxide-containing exhaust configured to to and separating carbon dioxide from carbon dioxide-containing exhaust accommodate separation assembly, at least one of stopping the cathode portion and the beam teoming cathode portions a fuel gas generation, and receive at least a portion of the fuel gas discharged from the device, and stopping the fuel cell assembly, the fuel cell assembly topping the beam teoming fuel cell assembly beams to use a much larger number of fuel in the fuel than the fuel cell assembly teoming It has a battery.