NOVELTY - The permselective-membrane reactor has reaction tube (1), separating column (4) having permselective membrane (5), discharge port (11), and modification-reaction catalyst (6). The source gas of ethanol is supplied from inlet, and catalytic reaction is performed to produce mixed gas of hydrogen, carbon monoxide and carbon dioxide. The hydrogen is permeated through permselective membrane, and recovered. The other gas components which are not permeated are discharged from gas outlet. The value of the hydrogen which is recovered is 60-99% at specific conditions.    USE - For manufacturing hydrogen used as petrochemical basic raw material gas for fuel cell.    ADVANTAGE - The method enables effective and efficient recovery of hydrogen. The disproportionation reaction of carbon monoxide and deactivation of catalyst by caulking are effectively suppressed.    DETAILED DESCRIPTION - The permselective membrane type reactor has reaction tube having gas inlet and gas outlet, separating column having permselective membrane which is inserted in concerning reaction and permeates hydrogen, discharge port in which cracked gas permeated from permselective membrane is discharged, and layer containing modification-reaction catalyst which promotes the modification-reaction of ethanol. The source gas containing ethanol is supplied from inlet port of reaction tube. Then, the catalytic reaction is carried out to produce mixed gas containing hydrogen, carbon monoxide and carbon dioxide. The hydrogen is separated and permeated through permselective membrane of separating column from the mixed gas, and discharged from discharge port. The other gas components which are not permeated through permselective membrane are discharged from outlet of reaction tube. The value of the hydrogen which is recovered is 60-99%, calculated by hydrogen recovery=100x(A/(A+B)) alpha=((CO2)/(CO)2)/K, where A is hydrogen quantity separated through permselective membrane, B is hydrogen quantity which is not permeated through selective membrane, alpha is 0.6 or more, CO2 is partial pressure of carbon dioxide in the exit of reaction tube, CO is partial pressure of carbon monoxide in the exit of reaction tube and K is equilibrium constant of disproportionation reaction of carbon monoxide at reaction temperature. The modification-reaction catalyst contains iron, cobalt, nickel, copper, molybdenum, ruthenium, rhodium, palladium, silver, tungsten, rhenium, osmium, iridium, platinum and/or gold. The permselective membrane is palladium membrane or palladium alloy membrane. An INDEPENDENT CLAIM is included for permselective-membrane type reactor.    DESCRIPTION OF DRAWING(S) - The figure shows the schematic sectional drawing of structure of the permselective-membrane type reactor in hydrogen-production method. (Drawing includes non-English language text)    Reaction tube (1)    Separating column (4)    Permselective membrane (5)    Modification-reaction catalyst (6)    Discharge port (11)