To provide an air conditioner and an air-conditioning method capable of significantly lowering temperature in comparison with a conventional cold air fan and reducing power consumption in comparison with a conventional air conditioner.

This air conditioner is roughly composed of an atomizing device 1 composed of an atomization nozzle 1a for jetting atomization water into the atmospheric air and an air nozzle 1b for distributing the dehumidification air toward the atomization water, a dehumidifying device 3 for conditioning the dehumidification air supplied to the atomizing device 1, a cooling device 2 for cooling the dehumidification air, a compressor 4 for distributing the compressed air to the dehumidification device 3, and a water tank 5 and a pressure water distribution pump 7 for supplying the atomization water to an atomizing device 8. The dehumidification air conditioned by the dehumidifying device 3 and cooled to be lower than the outside air temperature by the cooling device 2 is distributed to the atomization water jetted into the atmospheric air from the atomization nozzle 1a of the atomizing device, 1 from the air nozzle 1b of the atomizing device 1 to be distributed to and brought into contact with the atomization water. Thus the evaporation of the atomization water is enhanced, and the surrounding air can be rapidly cooled.