To enhance heat exchanging rate while reducing manufacturing cost and fixing cost by passing air through an air passage, i.e., the gap of air layers, and evaporating moisture absorbed onto a moisture absorbing material at normal temperature and performing heat exchange by absorbing heat being discharged from refrigerant at the time of liquefaction.
Refrigerant tube body 210 of an evaporation cooling machine is coated with a moisture absorbing material 202, i.e., the heat conduction contact face in an air passage 212 is coated with a moisture absorbing thin film material (moisture absorbing material 202), so that suction water from a water discharging unit adheres to the moisture absorbing material 202. Moisture adheres to the moisture absorbing material 202 when air is blown at high speed into the air passage 212 is evaporated at normal temperature and then condensed under extremely low cooling pressure by lowering the refrigerant temperature significantly. Further, function of the moisture absorbing material 202 is sustained by combining the moisture absorbing and moisture keeping functions thereof with the periodic moisture absorption ratio supplementary control of a moisture absorption control printed board. Since moisture absorption can be brought close to moisture evaporation, moisture absorption, collection and circulating can be dispensed with.