PURPOSE: To provide a hydrogen storage element having high rates of occlusion and release of hydrogen, and capable of keeping the function stably for a long period, by filling a hydrogen-storage metal in a porous casing.

CONSTITUTION: The hydrogen storage element 1A is composed of a porous, gas- permeable casing 2 made of metal, ceramics, glass, rubber, etc., and a hydrogen- storage metal 3 (e.g. Mg metal, La-Ni alloy, etc.) packing 20W90% of the inner space of the casing 2. When the casing 2 is made of an elastic material such as rubber, the packing ratio can be further increased.