NOVELTY - A hydrogen production apparatus comprises modifier (12) with which source gas containing methane as main component is supplied, carbon monoxide (CO) modifying device (13) to which gas modified by modifier is supplied, modification part (1) to obtain reformed gas which contains hydrogen and carbon dioxide by carrying out modification of CO contained in gas obtained by carrying out steam reforming process, and hydrogen separation part (2) which separates hydrogen from reformed gas obtained by modification part, obtains product gas, and collects gas after separating hydrogen as off-gas.    USE - A hydrogen production apparatus for fuel cell.    ADVANTAGE - Reforming process, CO modification, and hydrogen separation can be stably performed, and hydrogen can be stably produced.    DETAILED DESCRIPTION - A hydrogen production apparatus comprises modifier (12) with which source gas containing methane as main component is supplied, carbon monoxide (CO) modifying device (13) to which gas modified by modifier is supplied, modification part (1) to obtain reformed gas which contains hydrogen and carbon dioxide by carrying out modification of CO contained in gas obtained by carrying out steam reforming process, hydrogen separation part (2) which separates hydrogen from reformed gas obtained by modification part, obtains product gas, and collects gas after separating hydrogen as off-gas, off-gas supply path (L4) to send off-gas as fuel gas into combustion apparatus (12b), off-gas flow amount detection device (35) which detects flow volume of off-gas flowing through off-gas supply path, oxygen-containing gas supply path (L30) which supplies oxygen-containing gas required for combustion of off-gas supplied to combustion apparatus, and self-sustaining phase control unit (40ab) which controls amount of oxygen-containing gas supplied to combustion apparatus based on amount of off-gas flow detected by off-gas flow amount detection device. Steam reforming of source gas is performed by using heat generated by burning fuel gas in combustion apparatus provided in modifier.    DESCRIPTION OF DRAWING(S) - The drawing shows a block diagram of the hydrogen production apparatus. (Drawing includes non-English language text).    Modification part (1)    Hydrogen separation part (2)    Modifier (12)    Combustion apparatus (12b)    CO modifying device (13)    Off-gas flow amount detection device (35)    Self-sustaining phase control unit (40ab)    Off-gas supply path (L4)    Oxygen-containing gas supply path (L30)