The present invention is to provide a hydrogen supply device having a simple constitution which can be made small and light. In the present invention, a hydrogen occlusion tank is provided in a duct. A heat exchange tube is provided upstream from the hydrogen occlusion tank inside the duct. A first fan leads outside air into the duct, and cooling water, which has cooled a fuel cell, is led into the heat exchange tube. A hydrogen occluding alloy is accommodated in the hydrogen occlusion tank, and hydrogen released from the hydrogen occluding alloy is supplied via hydrogen supply pipes and a flow control valve to the fuel cell. Outside air passes through the heat exchange tube and is thereby heated; the heated outside air passes around the perimeter of the hydrogen occlusion tank, thereby heating the hydrogen occlusion tank.