An embodiment of the invention provides an air treatment device. The air treatment device comprises an air purifying unit configured to purify air a scent dispenser configured to dispense scent an air detector, configured to detect the purified air and provide an output signal and a processor configured to receive the output signal from the air detector and control the operation speed of the air purifying unit and the dispensing flow of scent dispensed by the scent dispenser, based on the output signal, wherein the dispensing flow of scent dispensed by the scent dispenser is decreased with the increase of the operating speed of the air purifying unit. Another embodiment of the invention provides a method of controlling a scent dispenser and an air purifying unit of an air treatment device, wherein the air treatment device further includes an air detector and a processor. The method comprises the steps of purifying air by using the air purifying unit detecting the purified air by using the air detector controlling, by using the processor, the operating speed of the air purifying unit and the dispensing flow of scent dispensed by the scent dispenser, based on the detection result, wherein the dispensing flow of scent dispensed by the scent dispenser is decreased with the increase of the operating speed of the air purifying unit.
