PURPOSE: To contrive miniaturizing, weight reducing, energy saving and cost down, by a method wherein an evaporating body, provided with the maximum evaporating area, is provided in a space to evaporate water from the evaporating body by the ventilation of a fan while capillary elevation is applied to the supplement of the evaporated water to the evaporating body.

CONSTITUTION: The water sucking layer 18 of an evaporating body 6 is dipped into a water tank 14 so as to arrive at a bottom surface while the evaporating body 6, a fixed plate 13 and the water tank 14 form an evaporating structure, constituted integrally so as to eliminate troubles for carrying them. An upper fan 15 is provided so that ventilated air flows through the wall body of the evaporating body 6 and either the ventilating direction or the sucking direction may be changed freely while a side surface fan 16 sends air into a given direction so that ventilating air flows on the surface of the evaporating body 6. Woven fabric and nonwoven fabric, manufactured by fibers containing much amount of cellulose series hydrophilic group, such as cotton, hemp, rayon or the like, is preferably used for the water sucking layer 18 by a method wherein the fabric is wound directly around the surface of a bearer or the bearer is covered by the bag of such fibers.