To provide an air conditioner requiring no water supply equipment.

A dehumidification is performed by a first adsorbent 3a and the air subjected to the dehumidification undergoes further dehumidification by a second adsorbent 5a. Moisture adsorbed by the first adsorbent 3a is released into air with the relative moisture lowered by the further dehumidification. This enables obtaining of a cooling capacity without requiring any water supply equipment for a larger freedom of installation in the installing of an air conditioner thereby achieving a reduction in installing cost. A significant drop in the moisture of air enables surely releasing of the moisture adsorbed by the first adsorbent 3a.