NOVELTY - A hydrogen-producing apparatus (10) consists of a reaction container (30) which accommodates hydrogen-producing agent (34) containing aluminum, in which reaction of hydrogen-producing agent and reaction solution (35) is carried out, a support portion (31) which enables suspension support of the hydrogen-producing agent from the upper portion of the reaction container, a hydrogen discharge portion (32) for discharging hydrogen gas, a reaction solution supply portion (33) which supplies water consumed by the reaction in the reaction container, and a control portion.    USE - Apparatus is used for producing hydrogen, and fuel cell system (all claimed).    ADVANTAGE - The hydrogen is produced using the apparatus, by simple process.    DETAILED DESCRIPTION - A hydrogen-producing apparatus consists of a reaction container which accommodates hydrogen-producing agent containing aluminum as a main component, in which reaction of hydrogen-producing agent and reaction solution containing alkali metal hydroxide is carried out in bottom portion, a support portion which enables suspension support of the hydrogen-producing agent from the upper portion of the reaction container, a hydrogen discharge portion for discharging hydrogen gas produced by the reaction of hydrogen-producing agent and reaction solution from the reaction container, a reaction solution supply portion which supplies water consumed by the reaction in the reaction container from the upper portion of the reaction container, and a control portion which controls the temperature of the reaction solution to predetermined value. The concentration of the alkali metal hydroxide in the reaction solution is maintained at predetermined value. The predetermined region of the lower end portion of the hydrogen-producing agent is contacted with the reaction solution, reaction byproduct which does not contain alkali metal is deposited on the bottom portion of the reaction container, and predetermined amount of hydrogen gas is produced. INDEPENDENT CLAIMS are included for the following:    (1) fuel cell system; and    (2) hydrogen production method.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view explaining hydrogen producing method using apparatus.    Hydrogen-producing apparatus (10)    Reaction container (30)    Support portion (31)    Hydrogen discharge portion (32)    Reaction solution supply portion (33)    Hydrogen-producing agent (34)    Reaction solution (35)    Deposit (37)