A fuel tank producing apparatus that allows the thickness of a resin on the surface of a tank container to be uniform and that is capable of improving the curing quality of the tank container. The fuel tank producing apparatus includes a conveyor for conveying the tank container, a plurality of heating chambers for heating the tank container during the conveyance, a cooling furnace for cooling the tank container at a position downstream of the plurality of heating chambers in the conveying direction, a gas supplier for supplying gas to the plurality of heating chambers, a plurality of nozzles for blowing the gas supplied from the gas supplier onto the surface of the tank container in the plurality of heating chambers, and a plurality of plug heaters for heating the gas between the gas supplier and the plurality of nozzles.