NOVELTY - The catalytic reformer comprises an air supply, and a separate fuel supply, where the reformer is divided into a first zone (6), which is provided for an exothermic reaction and into a second zone (7) arranged behind a flow direction of the fuel, where the second zone is provided for an endothermic reaction. A unit for heat transfer is provided, with which the heat from the first zone is transferred to the second zone. The first and second zones are enclosed by partition walls (14) and/or a wall (3). The partition walls and/or the walls are electrically heated.    USE - The catalytic reformer is useful for converting a fuel or a fuel mixture form fuel and air and/or water vapor in a hydrogen-containing gas for a fuel cell system, and forming a fuel-air mixture.    ADVANTAGE - The catalytic reformer is capable of rapidly and economically converting the fuel or the fuel mixture in an efficient manner.    DETAILED DESCRIPTION - The catalytic reformer comprises an air supply, and a separate fuel supply, where the reformer is divided into a first zone (6), which is provided for an exothermic reaction and into a second zone (7) arranged behind in a flow direction of the fuel, where the second zone is provided for an endothermic reaction. A unit for heat transfer is provided, with which the heat from the first zone is transferred to the second zone. The first and second zones are enclosed by partition walls (14) and/or a wall (3). The partition walls and/or the walls are electrically heated, comprise a metallic base support, and are coated with a catalyst material. The first and second zones are provided in a common housing (1). The unit for heat transfer has high heat-conducting common partition wall between the first and second zones. The first and second zones are thermally connected with each other. An intermediate zone is provided into the common housing, and is arranged in the flow direction of the fuel between the first and second zones, where the first and intermediate zones are thermally connected to each other by the unit for transferring heat in the form of a highly thermally conductive common second partition wall and/or the intermediate and second zones are thermally connected to each other by the unit for transferring heat in the form of a highly thermally conductive common third partition. The first and second partition walls are arranged such that a heat transfer is enabled by a thermal radiation from the second partition wall to the third partition wall. A preheater is provided in the common housing, and is arranged in the flow direction of the fuel before the first zone. The air supply in the flow direction is arranged before the preheating zone and the fuel supply behind the preheating zone. The first zone, the second zone and the preheating zone and/or the intermediate zone are arranged so that all the zones are coaxially arranged.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic view of a catalytic reformer for converting a fuel or a fuel mixture.    Housing (1)    Wall (3)    First zone (6)    Second zone (7)    Partition walls. (14)