NOVELTY - The power supply device comprises a first case (110) comprising an air hole, a second case (120) that is disposed in the first case and comprises a fuel cell (112), a battery module disposed in the first case, an air suction element such as a fan that is disposed in the first case and near the air hole and sucks an air into the first case through the air hole, a heat exchange module disposed in the first case for warming up the air, a passage formed between the first and second cases, and a fuel storage tank such as a hydrogen storage tank.    USE - The power supply device including a fuel cell is useful in portable electronic products, home power generating systems, transportation vehicles, military facilities, aerospace industry and small power generating systems.    ADVANTAGE - The power supply device including fuel cell exhibits low pollution and noise and high energy density and energy conversion efficiency, is a clean energy source with a promising future, and is capable of supplying power normally at a temperature below the freezing point of water such as high mountains and polar areas.    DETAILED DESCRIPTION - The power supply device comprises a first case (110) comprising an air hole, a second case (120) that is disposed in the first case and comprises a fuel cell (112), a battery module disposed in the first case, an air suction element such as a fan that is disposed in the first case and near the air hole and sucks an air into the first case through the air hole, a heat exchange module disposed in the first case for warming up the air, a passage formed between the first and second cases, and a fuel storage tank such as a hydrogen storage tank. The fuel cell and the battery module supply power to each other. After the air flows by the heat exchange module and is warmed up, a part of the air flows by the fuel cell and the battery module. The air flows by the heat exchange module, the fuel cell and the battery module through the passage. The first case further comprises an air relief valve (114), and an air discharge port (116) in communication with the second case. The air in the first case is discharged to an external environment through the air relief valve to adjust an air pressure in the first case. The residual air, after a reaction of the fuel cell, is discharged to the external environment through the air discharge port. A material of the first case comprises a thermal insulation material. The fuel cell is a proton exchange membrane fuel cell, a direct methanol fuel cell or a solid oxide fuel cell, and comprises a heat generating element. The air flows by the heat generating element and is warmed up. The battery module comprises a lithium ion battery, a lithium iron phosphate battery, a lead-acid battery, a nickel-metal hydride battery, or a dry battery. The heat exchange module comprises two heating plates, and a partition board disposed between the plates. The partition board forms a flow passage, and the air flows through the flow passage and is warmed up by the heating plates. The fuel storage tank is disposed in the first case for providing a fuel required by a reaction of the fuel cell. After the air is warmed up by the heat exchange module, a part of the air flows by the fuel cell, the fuel storage tank and the air suction element.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a power supply device.    First case (110)    Fuel cell (112)    Air relief valve (114)    Air discharge port (116)    Second case. (120)