NOVELTY - A hydrogen generating apparatus comprises main body (1) which generates fuel gas containing hydrogen by water vapor reforming reaction with source gas and water vapor, material supply device (2) which supplies source gas to hydrogen generating apparatus main body, water supply machine (3) which supplies water for water vapor reforming reaction to hydrogen generating apparatus main body, and combustor (4) which supplies heat required for water vapor reforming reaction to hydrogen generating apparatus main body by burning gas sent from exit of fuel gas.    USE - Hydrogen generating apparatus for fuel cell system (claimed) for household use.    ADVANTAGE - The apparatus reduces possibility of bad effect by raise of internal pressure in time of shutdown.    DETAILED DESCRIPTION - A hydrogen generating apparatus comprises main body (1) which generates fuel gas containing hydrogen by water vapor reforming reaction with source gas and water vapor, material supply device (2) which supplies source gas to hydrogen generating apparatus main body, water supply machine (3) which supplies water for water vapor reforming reaction to hydrogen generating apparatus main body and connects to exit of fuel gas of hydrogen generating apparatus main body through fuel gas path (5), combustor (4) which supplies heat required for water vapor reforming reaction to hydrogen generating apparatus main body by burning gas sent from exit of fuel gas, air supply device which supplies combustion air to combustor and controller that controls operation of air supply device and stops supply of source gas by material supply device and supply of water by water supply machine when stop process is started in state in which combustor is burning gas which flowed in through fuel gas path which then continue combustion in combustor and supply of combustion air by air supply combustion device. An INDEPENDENT CLAIM is included for a fuel cell system.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the hydrogen generating apparatus. (Drawing includes non-English language text).    Main body (1)    Material supply device (2)    Water supply machine (3)    Combustor (4)    Fuel gas path (5)