PURPOSE: To make the system for utilizing a hydrogen occluding alloy continu ous, to improve the operational stability, and to reduce the cost by using a liq. inert to hydrogen and the hydrogen occluding alloy or gaseous hydrogen to fluidize and transfer the hydrogen occluding alloy.

CONSTITUTION: A liq. (e.g., undecane and polystyrene) inert to hydrogen and a hydrogen occluding alloy (e.g., a titanium-iron alloy) or gaseous hydrogen is used as a medium to fluidize and transfer the hydrogen occluding alloy. In a thermally operated heat pump system, for example, hydrogen is circulated successively through a vessel 2, a vessel 3, a vessel 6, a vessel 5, and the vessel 2, an alloy 1 is circulated between the vessels 2 and 3, only a hydrogen occlud ing reaction is carried out in the vessel 2, and only a hydrogen releasing reac tion is carried out in the vessel 3. An alloy 4 is circulated between the vessels 5 and 6 in the same way, only a hydrogen occluding reaction is carried out in the vessel 5, only a hydrogen releasing reaction is carried out in the vessel 6, and the system is operated so that those reactions are continuously generated.