The utility model relates to a reformer which is provided with a catalyst container which comprises an interval in which a catalyst layer is formed and is configured to generate reformed gas through a reforming reaction accompanying heat absorption when
raw material gas flowing in from one end surface of the catalyst layer passes through the catalyst layer, the reformed gas flows out from the other end surface of the catalyst layer; a plurality of reformed gas tubes which penetrate the catalyst layer and through which the reformed gas flows; and a heating device for heating the reformed gas in a section between the flow of the reformed gas out of the catalyst layer and the flow of the reformed gas into the plurality of reformed gas tubes. As a result, in the reformer that uses the catalyst to promote an endothermic reaction, i.e., a reforming reaction from the
raw material gas to the reformed gas, the
energy consumption of the heating device provided in the reformer can be reduced.