To provide a zeolite-water system heat pump system using zeolite having a moisture separating quantity larger than conventionally known zeolite in a low temperature area of 80°C or less, and also to provide an applied appara tus such as an air conditioner using this heat pump system.

The zeolite having the moisture separating quantity of a value of 14 wt.% or more when hydrated BEA type zeolite is heated at a temperature of 80°C under a reduced pressure of 1 Torr or less, is used for this heat pump system. This heat pump system is also used for the applied apparatus.