NOVELTY - The thin reformer for fuel cell comprises, substrate (10) in which a flow path is formed, fuel-filling section for filling the flow path with fuel, a reformer section (40), a carbon monoxide (CO)-remover and a cover for covering an upper section of the substrate and sealing the flow path to exterior, and an evaporator for the liquid fuel. The reformer section is intended for forming a flow path on a side of the fuel filling section in the substrate, in order to reform the fuel in hydrogen gas by heat-absorbing reaction.    USE - Used in the fuel cells.    ADVANTAGE - The reformer is simple and can be manufactured easily as well as guarantees increased reaction efficiencies of the reform section and the CO-removers.    DETAILED DESCRIPTION - The thin reformer for fuel cell comprises, substrate (10) in which a flow path is formed, fuel-filling section for filling the flow path with fuel, a reformer section (40), a carbon monoxide (CO)-remover and a cover for covering an upper section of the substrate and sealing the flow path to exterior. The reformer section is intended for forming a flow path on a side of the fuel filling section in the substrate, in order to reform the fuel in hydrogen gas by heat-absorbing reaction. The CO-remover is intended for forming a flow path on an opposite side of the fuel filling section, in order to remove CO-gas contained in the hydrogen gas from the hydrogen gas by heat radiation. The reformer section is connected with a wide flow path section of the CO-remover by a connecting section with an area, which has less cross section than the wide flow path section. The evaporator (30) is formed between an output end of the fuel filling section and the reformer section. The liquid fuel is heated up by a heating element, which is formed on a lower surface of the substrate. The evaporator exhibits dividing walls (34) for forming a zigzag flow path. The flow path of the reformer section is formed in a zigzag flow path same as or more larger than the evaporator and exhibits catalyst from copper/zinc oxide or copper/zinc oxide/alumina, which is formed on its dividing walls and are filled in the zigzag flow path. The heating element of the reformer section from an electrically adjustable resistance conductive strip is formed on the floor space of the substrate and heats the reformer section through the substrate. The CO-remover forms a flow path by dividing walls, which are coated with catalysts particles from platinum, platinum/ruthenium or copper/cerium oxide/alumina. The heating element (36) of the CO-remover is formed on a lower surface of the substrate and heats the CO-remover through the substrate. Deep flow paths formed in the cover correspond to the flow paths of the fuel filling section, the evaporator, the reformer section and the CO-remover and increase the interior volume of the flow paths formed by the substrate and the cover. The fuel filling section separates the heat-absorbing reaction and heat radiating reaction of the CO-reformer and causes a reforming reaction.    DESCRIPTION OF DRAWING(S) - The drawing shows a thin reformer for fuel cell:    Substrate; (10)    Evaporator; (30)    Dividing walls; (34)    Heating element (36)    Reformer section. (40)