NOVELTY - Hydrogen-production apparatus has reaction unit (110) for producing sulfuric-acid and hydrohalide aqueous solutions (A,B), separation unit (120), sulfuric-acid concentration and decomposition units (160,170), oxygen electrolytic-parting unit (180), hydrohalide concentration unit (130), halogenated hydrocracking unit (140) for decomposing concentrated hydrohalide into halogen and hydrogen, and halogen-recycling unit (150).    USE - For producing hydrogen used for fuel cells used for generating electric power (claimed).    ADVANTAGE - The hydrogen-production apparatus has excellent thermal efficiency, and efficiently produces hydrogen.    DETAILED DESCRIPTION - A hydrogen-production apparatus has a reaction unit (110) for reacting halogen such as iodine or bromine, sulfur dioxide and water, to produce sulfuric-acid aqueous solution (A) and hydrohalide aqueous solution (B), a separation unit (120) for separating solutions (A,B) by specific gravity difference, a sulfuric-acid concentration unit (160) for concentrating solution (A), a sulfuric-acid decomposition unit (170), an oxygen electrolytic-parting unit (180), a hydrohalide concentration unit (130), a halogenated hydrocracking unit (140), and a halogen-recycling unit (150). The unit (170) decomposes the concentrated sulfuric acid into sulfur dioxide and water, and unit (180) separates oxygen from sulfur trioxide and water by oxygen-permeating film. The unit (130) concentrates the separated hydrohalide aqueous solution, and unit (140) decomposes the concentrated hydrohalide into halogen and hydrogen. The unit (150) separates hydrogen from units (180,140) by hydrogen permeable film (151), and recycles halogen and sulfur dioxide to the reaction unit.    DESCRIPTION OF DRAWING(S) - The figure shows the outline block diagram of the highly efficient hydrogen generation reaction in the hydrogen-production apparatus. (Drawing includes non-English language text).    reaction unit (110)    separation unit (120)    hydrohalide concentration unit (130)    halogenated hydrocracking unit (140)    halogen recycling unit (150)    sulfuric-acid concentration unit (160)    sulfuric-acid decomposition unit (170)    oxygen electrolytic-parting unit (180)