TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Method: A substance (S), which has a function to make hydrogen atom dissociate hydrogen molecule, is added to the carbonaceous material.The substance (S) contains one or two or more types of manganese, iron, cobalt, nickel, platinum, palladium, rhodium, lithium, boron, sodium, magnesium, potassium, iridium, neodymium, lanthanum, calcium, vanadium, titanium, chromium, copper, zinc, aluminum, silicon, ruthenium, silver or their alloys.The substance (S) is preferably contained as structural component, an oxide, nitride or chloride.The total amount of substance is 0.3-20 mass% of hydrogen storage constitution amount.A catalyst component for hydrogenation is added to the carbonaceous material before mechanical grinding and/or during grinding. The catalyst component is removed before dehydrogenation, using a chemical agent.Dehydrogenation is performed by heat processing in vacuum, in inert gas or mixed gas of inert gas and oxygen gas, at temperature range of room temperature to 600 degreesC.Preferred Material: Hydrogen is stored in the surface and/or inside of dehydrogenated carbonaceous material.The carbonaceous material is graphite, amorphous carbon activated carbon, carbon nanotube or fullerene. EXAMPLE - Graphite powder of average particle diameter 36 microns (1.95 g) and hydrogenation catalyst (iron of average particle diameter 20 nm and specific surface area 46 m2/g), were added to a container made of zirconia. The container was evacuated and 1.0 MPa of hydrogen gas was introduced. Mechanical grinding was carried out. The milled sample was dehydrogenated in vacuum by heat processing at 600 degreesC for 2 hours in presence of inert gas (high purity argon, high purity nitrogen). Palladium microparticles of average particle diameter 0.5 microns and specific surface area 1.2 m2/g, were added to the dehydrogenated material. Hydrogen storage material carrying the dissociation catalyst, was obtained. The hydrogen storage material had high hydrogen storage capability.