NOVELTY - A hydrogen supply system has fuel storage unit (1) to store aqueous solution of water-soluble organic compound, electrolysis unit (2) to electrolyze aqueous solution from fuel storage unit and produce hydrogen and carbon dioxide, carbon dioxide recovering unit (13) to recover carbon dioxide from unit (2), hydrogen recovering unit (12) to recover hydrogen from unit (2), oxygen reaction unit (72) to react oxygen with recovered hydrogen and produce water or water vapor, and hydrogen supply unit (30) to supply recovered hydrogen to hydrogen supply destination.    USE - For manufacturing and supplying hydrogen to fuel cell used in electric vehicle such as hydrogen fuel battery motor vehicle.    ADVANTAGE - The hydrogen supply system produces and recovers hydrogen and carbon dioxide efficiently and economically.    DETAILED DESCRIPTION - A hydrogen supply system manufactures and supplies hydrogen from water-soluble organic compound and water. The hydrogen supply system has fuel storage unit to store aqueous solution of water-soluble organic compound, electrolysis unit (2) to electrolyze aqueous solution from fuel storage unit and produce hydrogen and carbon dioxide, carbon dioxide recovering unit (13) to recover carbon dioxide from unit (2), hydrogen recovering unit (12) to recover hydrogen from unit (2), oxygen reaction unit (72) to react oxygen with recovered hydrogen and produce water or water vapor, and hydrogen supply unit (30) to supply recovered hydrogen to hydrogen supply destination.    DESCRIPTION OF DRAWING(S) - The figure shows the structure of hydrogen supply system. (Drawing includes non-English text)    Fuel storage unit (1)    Electrolysis unit (2)    Hydrogen recovery unit (10)    Carbon dioxide recovery unit (13)    Hydrogen purifying unit (25)    Hydrogen pressurizing unit (27)    Hydrogen storage unit (28)    Hydrogen supply system (30)    Carbon dioxide pressurizing unit (35)    Carbon dioxide supply unit (38)    Oxygen reaction unit (72)    Water recovery unit (73)