PURPOSE: To efficiently and rapidly increase the temperature of a catalyst and shorten the starting time, by heating the catalyst from the inside and outside with superheated vapor produced by combustion of a burner and evaporator, heating the catalyst to a given reforming temperature and starting reforming reaction.

CONSTITUTION: Methanol is fed from a feed source 3 to a burner 11 and burned to heat an evaporator 13 and reforming reactor 15 in a combustion chamber 12. When the temperature of a catalyst 4 exceeds the methanol evaporation temperature, the methanol is fed to the evaporator 13 under a command of a controlling part 5 and the evaporated superheated vapor is passed through the reforming reactor 15 to heat the catalyst 14. When the catalyst temperature exceeds 100°C, the feed of the methanol is stopped to feed water from a feed part 4 to the evaporator 13 and pass the superheated vapor to the reforming reactor 15. When the catalyst is further heated to a high temperature and attains ≥200°C corresponding to the given reforming reaction temperature, a blend of the methanol with water is then fed to the evaporator 13 to start the reforming reaction and convert the methanol into hydrogen-rich gas, which is then delivered from a reforming apparatus 1.