NOVELTY - A hydrogen generating apparatus (1) comprises heating pipe (2) and outer cylinder (3) which center axis overlaps with center axis of heating pipe, partition pipe (4) which forms flow path of gas, material supply part (5) which supplies source gas on opposite side to folding part of flow path of gas, water supply part which supplies water on opposite side to folding part of flow path of gas between heating pipe and partition pipe, and modification part which reforming-reacts source gas and water vapor using modification catalyst.    USE - Hydrogen generating apparatus for fuel cell.    ADVANTAGE - The apparatus rapidly heats to temperature which activates the whole denaturation catalyst and shortens starting time.    DETAILED DESCRIPTION - A hydrogen generating apparatus (1) comprises heating pipe (2) and outer cylinder (3) which center axis overlaps with center axis of heating pipe, partition pipe (4) which forms flow path of gas, material supply part (5) which supplies source gas on opposite side to folding part of flow path of gas between heating pipe and partition pipe, water supply part which supplies water on opposite side to folding part of flow path of gas between heating pipe and partition pipe, modification part which reforming-reacts source gas and water vapor using modification catalyst arranged between heating pipe and partition pipe in folding part vicinity of flow path of gas, denaturation part which reduces carbon monoxide in hydrogen-containing-gas generated by modification part using denaturation catalyst arranged between outer cylinder and partition pipe, combustion part which is arranged inside heating pipe and heats modification part, heat insulation wall which opens space used as air path between parts located in outer periphery direction of denaturation catalyst in outer cylinder, air extraction opening connected as flow of hydrogen-containing gas that flows through denaturation catalyst in space is downstream, and air supply unit which supplies air so that external air may enter into space from air intake and may come out of air extraction opening at time of starting.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic block diagram of the hydrogen generating apparatus. (Drawing includes non-English language text).    Hydrogen generating apparatus (1)    Heating pipe (2)    Outer cylinder (3)    Partition pipe (4)    Material supply part (5)