Disclosed is an apparatus and method for controlling an air cleaning. The apparatus includes an air cleaning element, an AC high-voltage generator and a control unit. The air cleaning element generates negative ions and ozone using plasma discharge, and cleans indoor air using the negative ions and ozone. The AC high-voltage generator generates an AC high-voltage, and applies the AC high-voltage to the air cleaning element. The control unit varies at least one of the AC voltage and AC frequency applied to the air cleaning element by the AC high-voltage generator depending on a state of indoor air being cleaned using the air cleaning element. Therefore, it is possible to effectively generate negative ions while minimizing ozone generation to an acceptable level depending on a state of indoor air, thereby increasing air cleaning performance so as to sterilize and clean contaminants more efficiently.