PURPOSE: To provide a negative ion air generating device having a relatively simple configuration and having a function of removing air pollution substance and another function of humidifying air.

CONSTITUTION: A mist chamber 6 is disposed in a housing 1 provided with an air suction port 2 and an air discharging port 3, this mist chamber is provided with rotary plates 10 and 11 rotated by a motor 13, water is fed from a water supplying means 7 to the rotary plates, this water is sprinkled around it with a centrifugal force produced by the rotation of the rotary plates to atomize water, air sucked from the air suction port is contacted with the water particles to produce negative ion air, this negative ion air is supplied from the air discharging port. With such an arrangement, the water is sprinkled with the centrifugal force under the rotation of the rotary plates to make fine water particles and then the negative ions are given to the air under a Lenared effect.