NOVELTY - Liquid modification raw material containing liquid hydrocarbon fuel (A) and water (B) is pressurized and modified to obtain hydrogen rich gas (D). The gas is contacted with adsorption agent, and carbon monoxide is absorbed and removed. Hydrogen storage material capable of occluding hydrogen in gas is produced. The occluded hydrogen is discharged, and thus highly pure hydrogen (F) is manufactured. Adsorption agent is obtained by supporting copper halide (I) and/or copper halide (II) on support chosen from silica, alumina, activated carbon, graphite and polystyrene-type resin.    USE - Manufacture of highly pure hydrogen used for proton conduction form fuel cell e.g. phosphoric acid form fuel cell and solid form fuel cell.    ADVANTAGE - The hydrogen is economically manufactured with high purity and improved energy efficiency using compact apparatus.    DETAILED DESCRIPTION - Liquid modification raw material containing liquid hydrocarbon fuel and water is pressurized in liquid state. The pressurized raw material containing carbon monoxide is modified to obtain hydrogen rich gas. The hydrogen rich gas is contacted with a carbon monoxide adsorption agent, and carbon monoxide is absorbed and removed without pressure-reducing hydrogen rich gas containing carbon monoxide to obtain carbon monoxide-removed gas. Hydrogen storage material capable of occluding hydrogen in gas is produced without pressure-reducing carbon monooxide-removed gas. The occluded hydrogen is discharged from occlusion material, and thus highly pure hydrogen is manufactured. The adsorption agent is obtained by supporting copper halide (I) and/or copper halide (II) on support chosen from silica, alumina, activated carbon, graphite and polystyrene-type resin.    DESCRIPTION OF DRAWING(S) - The drawing shows the flowchart illustrating manufacture of highly pure hydrogen.    Modifier (1)    Transformer (2)    Carbon monoxide removal device (5)    Hydrogen separation and recovery apparatus (6)    Liquid hydrocarbon fuel (A)    Water (B)    Hydrogen rich gas (D)    Highly pure hydrogen (F)