A fuel cell fuel contains an organic fuel used as a fuel for a fuel cell. The organic fuel is in a form of a solid molecular compound, such as an inclusion compound. The molecular compound can be prepared by contact catalytic reaction of a compound for forming the molecular compound and the organic fuel, and allows a liquid organic fuel to be in a solid compound to store the organic fuel stably in a relatively lightweight form. The molecular compound easily releases the organic fuel by, for example, heating, and the organic fuel is supplied to the fuel electrode of a fuel cell. Thus, the handleability of the fuel cell fuel containing the organic fuel can be improved, and the problems of corrosion, freezing of the fuel, crossover, and so forth can be solved.