NOVELTY - A hydrogen generation system comprises hydrogen generation reaction section for containing liquid mixture of formic acid and ionic liquid, and decomposing the acid into hydrogen and carbon dioxide by heating; and separation section for separating mixture of hydrogen and carbon dioxide supplied from hydrogen generation section into hydrogen and carbon dioxide, where after separation, hydrogen is sent out of separation section to external hydrogen destination, and carbon dioxide is sent out of separation section to external carbon dioxide destination or emitted into atmosphere.    USE - For generating hydrogen (claimed). The system is connected to commercial or home fuel cells and to a hydrogen turbine (hydrogen combustion turbine) as a hydrogen supply source.    ADVANTAGE - The system continuously generate hydrogen from formic acid at low cost while supplying formic acid to the hydrogen generation reaction section and while repeatedly using the ionic liquid. Thus the system can be loaded onto hydrogen fuel vehicles, such as those equipped with a hydrogen engine and/or a fuel cell that need a hydrogen source. Compared with the form of high pressure hydrogen gas stored in a cylinder and the form of hydrogen liquid contained in a very low temperature cylinder, the hydrogen generation system is more useful for mobiles and automobiles like hydrogen fuel cars because of the safe, compact, and low-cost hydrogen storage form. The system can constitute a cogeneration system that performs hot water supply, heating, power generation, and the like with the heat energy accompanying power generation by a fuel cell or hydrogen turbine. By the hydrogen generation method, it is possible to solve such hydrogen problems as the production cost, safety, cost, and storage efficiency that are met in the industry-scale generation of hydrogen.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for generating hydrogen involving: heating a liquid mixture of formic acid and an ionic liquid to generate hydrogen using the hydrogen generation system.