TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Reactions: Carbon monoxide or carbon dioxide and hydrogen are generated from the chemical compound from which hydrogen is obtainable and water vapor under ordinary pressure at 800degreesC, preferably 500degreesC in reforming reaction. In hydrocarbon decomposition reaction, carbon and hydrogen are generated from the chemical compound from which hydrogen is obtainable under ordinary pressure at 500degreesC. The chemical compound from which hydrogen is hardly obtainable is an alcohol having two or more carbons, the chemical compound from which hydrogen is obtainable is hydrocarbon, and the reaction for converting the alcohol into the hydrocarbon is dehydration reaction. The chemical compound from which hydrogen is hardly obtainable is an ester having two or more carbons, the chemical compound from which hydrogen is obtainable is hydrocarbon, and the reaction for converting the alcohol into the hydrocarbon is a combination of hydrolysis reaction in which the ester is decomposed by the hydrolysis to yield alcohol and dehydration reaction in which the resulting alcohol is dehydrated and converted into the hydrocarbon. The chemical compound from which hydrogen is hardly obtainable is an amine having one or more carbons, the chemical compound from which hydrogen is obtainable is hydrocarbon, and the amine is converted into the hydrocarbon by deamination. The chemical compound from which hydrogen is hardly obtainable forms an azeotropic compound with water in the raw material. An additive for breaking azeotropic relation between the chemical compound and water chosen from sodium carbonate, sodium chloride, sodium acetate, potassium chloride, potassium acetate, potassium iodide, calcium chloride, calcium bromide, barium chloride, magnesium chloride and magnesium bromide, is added to the raw material by an addition unit, and the raw material is subjected to distillation or fractional distillation to condense the chemical compound from which hydrogen is hardly obtainable in a condenser followed by performing the conversion reaction.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Catalysts: The hydrocarbon decomposition catalyst (15) used in hydrocarbon decomposition reaction is a nickel catalyst or a precious metal catalyst containing palladium, rhodium and/or platinum. The conversion catalyst (12) used for conversion reaction is alumina catalyst, silica catalyst, zeolite catalyst, alkali-treated zeolite catalyst, alkali-treated alumina catalyst, alkali-treated silica catalyst, alkali-treated silica alumina catalyst and/or silica alumina catalyst. A reforming catalyst is used for reforming reaction. SPECIFIC COMPOUNDS - The alcohol is 2-propanol, and the hydrocarbon is propene.    EXAMPLE - 2-propanol with 99.9% or more purity was supplied from a raw material tank at a speed of 0.23 cm3/min to a vaporizer, and vaporized at 180degreesC, followed by diluting with nitrogen with 99.9999% or more purity to provide a total flow of 500 cm3/min. Subsequently, the raw material gas was passed through a silica alumina catalyst with a content of alumina of 13% and BET specific surface area of 430 m2/g as a conversion catalyst in a converter under atmospheric pressure at 300degreesC. 2-propanol was dehydrated to obtain propene with a yield of 93%. The gas including the propene was mixed with water vapor at a volume ratio of 1:8. The mixed gas was passed through a nickel bearing alumina catalyst with nickel-bearing ratio of 0.5% and BET specific surface area of 40 m2/g with a mixed gas flow of 100 cm2/min under atmospheric pressure at 800degreesC. Propene was subjected to steam reforming reaction, where the reaction ratio of propene was 96% and the actual yield of hydrogen corresponded 91% of the theoretical yield.