NOVELTY - A hydrogen production apparatus comprises modification part (21) which makes raw fuel gas and water vapor react under high temperature and modifies to hydrogen rich reformed gas, inorganic hydrogen separation membrane which carries out membrane separation of highly purified hydrogen from reformed gas from transformation part which makes reformed gas contact a conversion catalyst and transforms carbon monoxide in reformed gas, cooling unit (5) which cools reformed gas supplied to transformation part, and transformation temperature control unit which adjusts amount of cooling of cooling unit.    USE - An apparatus for producing hydrogen (claimed).    ADVANTAGE - Lifetime of the inorganic hydrogen separation membrane is improved.    DETAILED DESCRIPTION - A hydrogen production apparatus comprises modification part (21) which makes raw fuel gas and water vapor react under high temperature and modifies to hydrogen rich reformed gas, inorganic hydrogen separation membrane (34) which carries out membrane separation of highly purified hydrogen from reformed gas from transformation part (33) which makes reformed gas contact a conversion catalyst (35) and transforms carbon monoxide in reformed gas, cooling unit (5) which cools reformed gas supplied to transformation part, and transformation temperature control unit (51) which adjusts amount of cooling of cooling unit and controls temperature of transformation part to predetermined reference temperature. Transformation part and inorganic hydrogen separation membrane are integrated transformation separation unit (30) by the form which adjacently arranges conversion catalyst to upstream surface of inorganic hydrogen separation membrane.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of the hydrogen production apparatus. (Drawing includes non-English language text).    Cooling unit (5)    Modification part (21)    Transformation separation unit (30)    Transformation part (33)    Inorganic hydrogen separation membrane (34)    Conversion catalyst (35)    Transformation temperature control unit (51)