An adsorption type air cooler which has a high coefficient of performance and can be stably operated over a long term. When a refrigerant vapor having evaporated by heat exchange with a load water in a refrigerant storage tank serving as an evaporator is adsorbed by an adsorbent heat exchanger, a cooling water for removing heat of adsorption is conventionally caused to circulate at a constant temperature and a constant flow rate normally determined by circumstances while according to the invention as claimed in claim (1) a temperature and a flow rate of the cooling water for removal of heat of adsorption are artificially controlled depending upon a cold output of the load water by making use of a cooling water heated after removal of heat of adsorption or a heat source water. The invention as claimed in claim (1) is an invention, in which a refrigerant storage tank and a load heat exchanging section are provided separately from each other, and a load cooler is provided for causing heat exchange between a refrigerant liquid supplied from the refrigerant storage tank through a pump and a load to cool the load while evaporating a part of the refrigerant so that gas-liquid separation is effected by returning to the refrigerant storage tank the refrigerant liquid having performed heat exchange in the load cooler, a refrigerant vapour and a mixed fluid thereof. As the refrigerant storage tank and the load heat exchanging section are provided separately from each other, an evaporative latent heat of the refrigerant is utilized independently of temperature change in the refrigerant storage tank to effect heat exchange between the refrigerant and the load whereby a load heat of a constant temperature can be obtained.