The present invention provides device and method for controlling air cleaning operation, in which an air conditioner with an air cleaner is made to clean air effectively proper to different pollutants. The device includes a memory having a plurality of operation modes set and stored therein for controlling operation of a fan proper to characteristics of air pollution sources, first means for selecting one of the plurality of operation modes stored in the memory, and a controlling part for controlling the fan according to a control program of the operation mode. The method includes the steps of selecting one of a plurality of operation modes, changing setting of an operation time period of the selected operation mode, reading the selected operation mode from the memory, and changing the operation time period of the operation mode to the set value, and controlling the fan according to the value of the changed operation time period and the value of the operation mode read from the memory.