In order to investigate zeolite-water heat pump system, a small trial model of the system has been made. The heat pump loaded with only 350g of zeolite powder in the bed operated successfully in making ice, and recorded the lowest temperature of 255K through the successive sublimation of ice. As many joints were necessary for vacuum-connection of glass tubes, “bite type fittings”, which are commercially available for hydraulic use of such as air-conditioners, were machined partially to fit for the heat pump fabrication. The low price, high vacuum resisting and mechanically strong natures of the joint serve much for the investigation. Present and future research subjects to develop the heat pump system are briefly described.