NOVELTY - Invention relates to chemistry and can be used for producing hydrogen and methane. The device has a case 1, a reactor for vapour conversion of hydrocarbon fuel 2, with a burner 3 inside it, a reactor for vapour conversion of carbon monoxide 4, a reactor for selective methanation 5 or reactor for selective methanation 5 and a reactor for selective oxidation of carbon monoxide 6, vapour generator 7, stream distributor 8 with channels for carrying reformate and products of combustion of hydrocarbon fuel, two heat-insulation units 9 and 10, fitted in line with the reactor for vapour conversion of hydrocarbon fuel 2 and vapour generator 7 with formation of annular channels between them for carrying heat to the reformate. Heat-insulation units 9 and 10 are fitted on both sides of the vapour generator 7, which is made in form of a screw conveyor and is installed in line with the reactor for vapour conversion of hydrocarbon fuel 2. Between the inner surface of the case 1 and the outer surface of the heat insulation unit 10, adjacent to the vapour generator 7, there is a heat exchanger 11, made in form of two coaxial pipes 23 and 24, separated from each other by at least one longitudinal baffle 25, fitted with a gap from the bottom end of the pipes. The reactor for vapour conversion of carbon monoxide, reactor for selective methanation 5 or reactor for selective methanation and reactor for selective oxidation of carbon monoxide 6 are joined on the height, and catalysts for these reactors are separated from each other by inert filling material or separating grids 14. The reactor for vapour conversion of hydrocarbon fuel is joined to the vapour generator 7 by pipes 15. In the bottom part of the annular gap between the outer surface of the vapour generator and the inner surface of the heat-insulating unit there is a collector 16 for collecting reformate coming out of the reactor for vapour conversion of hydrocarbon fuel, joined by pipes 17 with each pipe 12 of the reactor for vapour conversion of carbon monoxide 4. The device also has a flame control sensor 18, water and natural gas mixer 19, connecting pipe for inlet and outlet of reagents 20, heat insulation 21, ignition plug 22, thermocouple for monitoring temperature of structural components of the device. Temperature conditions for vapour conversion of hydrocarbon fuel and vapour conversion of carbon monoxide are regulated using the burner by varying flow of hydrocarbon fuel and excess air factor. Temperature conditions during fine purification of hydrogen-bearing gas from carbon monoxide are regulated by using air, which is further transferred to the burner, as heat carrier.    USE - Chemistry.    ADVANTAGE - Invention increases efficiency of the process. 2 cl, 4 dwg