NOVELTY - The hydrogen producing apparatus for operation of fuel cells, comprises reformer (3) for transforming hydrocarbon gas and water into hydrogen and further reformer products, and heat exchangers (4) arranged upstream to the reformer. For the chemical processing of the reformer products, heat delivering catalyst stages (5, 6, 7) are arranged, which are provided with reaction-specifically adapted and temperature-specifically designed heat exchangers, have a temperature gradient profile descending from the reformer to the last catalyst stage, are attached downstream to the reformer.    USE - For operating fuel cells.    ADVANTAGE - The apparatus ensures more efficient transformation of hydrocarbon gas and water into hydrogen and completely reduces the formation of harmful carbon monoxide during the production of the hydrogen. The parts or components of the apparatus are more compact.    DETAILED DESCRIPTION - The hydrogen producing apparatus for operation of fuel cells, comprises reformer (3) for transforming hydrocarbon gas and water into hydrogen and further reformer products, and heat exchangers (4) arranged upstream to the reformer. For the chemical processing of the reformer products, heat delivering catalyst stages (5, 6, 7) are arranged, which are provided with reaction-specifically adapted and temperature-specifically designed heat exchangers, have a temperature gradient profile descending from the reformer to the last catalyst stage, are attached downstream to the reformer. The heat exchanger arranged upstream to the reformer, is used for the preheating the hydrocarbon gas and water and is connected with the downstream heat exchangers under the formation of heat transfer adapted to the catalyst steps and to the temperature profile. All the components of the apparatus are arranged in a housing with inlet- and discharge connections. The reformer is provided with a heater as a burner (1) for the further heating of the hydrocarbon gas and water. The burner is built for the combustion of a part of the hydrocarbon gas supplied to the reformer. The reformer is cylindrical or pot-shaped and partly encloses the burner. The burner is provided with an exhaust system (2), which is connected with the upstream heat exchangers under the formation of heat transfer adapted to the catalyst steps and to the temperature profile. The exhaust system is built in the form of a ring channel enclosing the reformer and the catalyst stages. The heat exchanger is built in the form of spiral tube arranged in the ring-channel-shaped exhaust system. The reformer is built as an autothermal reformer for the flame-free combustion of hydrocarbon gas, water and air supplied over the heat exchanger. During the flame-free combustion, the catalyst stages are additionally built as an exhaust system. The spiral tube encloses the reformer and the catalyst stages.    DESCRIPTION OF DRAWING(S) - The figure shows a hydrogen producing apparatus:    Burner; (1)    Exhaust system; (2)    Reformer; (3)    Heat exchangers; (4)    Catalytic stages. (5, 6, 7)