NOVELTY - A hydrogen generating apparatus has modifier which generates hydrogen-containing gas using source gas, source gas supply path, hydrodesulfurization device which removes sulfur compound contained in the source gas, recycle flow path which supplies hydrogen-containing gas from the modifier to the source gas before flowing into the hydrodesulfurization device, pressure detector which detects the pressure of upstream source gas supply path, rate controller provided in the recycle flow path, and controller which controls the rate controller according the pressure detector.    USE - Hydrogen generating apparatus for fuel cell system (claimed).    ADVANTAGE - Possibility that the flow volume of hydrogen-containing gas added to source gas will be less than required amount is reduced.    DETAILED DESCRIPTION - A hydrogen generating apparatus has modifier which generates hydrogen-containing gas using source gas, source gas supply path where source gas supplied to the modifier flows, hydrodesulfurization device which removes the sulfur compound contained in the source gas supplied to the modifier, recycle flow path which supplies hydrogen-containing gas from the modifier to the source gas before flowing into the hydrodesulfurization device, pressure detector which detects the pressure of upstream source gas supply path rather than merging location with the recycle flow path, rate controller provided in the recycle flow path, and controller which controls the rate controller according the detected value from the pressure detector so that the volume ratio of the hydrogen-containing gas added to source gas through the recycle flow path is more than the lower limit. An INDEPENDENT CLAIM is included for fuel cell system.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic diagram of the hydrogen generating apparatus. (Drawing includes non-English language text).    Modifier (1)    Combustor (2)    Source gas supply path (3)    Hydrodesulfurization device (5)    Source gas supply device (6)    Pressure detector (7)    Recycle flow path (8)    Rate controller (10)    Controller (11)    Hydrogen generating apparatus (100)