To improve the storage speed of hydrogen into a hydrogen storage material by providing a tank in which the material is stored, a hydrogen supply means to supply molecular hydrogen into the tank, and a storage facilitating means to heat the molecular hydrogen in the tank to separate into atomic hydrogen.

Hydrogen is stored in a hydrogen storage alloy 12 in a hydrogen storage device, an opening/closing valve is opened to supply gaseous molecular hydrogen is supplied into a tank 11 through a hydrogen supply/discharge tube 13 from a hydrogen source. The temperature of the alloy 12 is set to be in the vicinity of the room temperature by a temperature control member 17. The supplied molecular hydrogen is heated to about 1,300°C by means of a tungsten filament 16 at a sideward part of a hydrogen supply/discharge tube 13. At this time, the molecular hydrogen is partly separated into atomic hydrogen by the catalytic action of the filament 16. The separated hydrogen is absorbed in the surface of the alloy 12, and then dispersed therein.