Provided an air cleaning system, which includes: a first reactor which has a first inlet and a first outlet and in which a channel is formed; a first moisture adsorption filter and a first water-soluble gas pollutant adsorption filter that are provided inside the first reactor and are provided so that a gas passes therethrough sequentially while flowing along the channel from the first inlet to the first outlet; a plurality of first magnetrons that are provided at a lateral portion of the first reactor so as to correspond respectively to the first moisture adsorption filter and the first water-soluble gas pollutant adsorption filter and selectively apply microwaves to the first moisture adsorption filter and the first water-soluble gas pollutant adsorption filter; and a heat exchanger that receives hot air containing a water-soluble gas pollutant and moisture, both of which are desorbed from the first moisture adsorption filter and the first water-soluble gas pollutant adsorption filter and are discharged by the first outlet, condenses the moisture into water, and dissolves and discharges the water-soluble gas pollutant in the condensed water. According to the present invention, the air cleaning system can unify a dehumidifying process and a water-soluble gas pollutant removing process to simplify an air cleaning process, recover and recycle waste heat by introducing microwaves and the heat exchanger so as to contribute to energy saving, and be used semi-permanently without a need to periodically replace a filter.