To provide an air purifier for promoting to quit smoking.

This air purifier is provided with a motor 6 for rotating a fan generating a current of air, a cigarette detecting means 1 for detecting a flame used in smoking, and a means for displaying the number of cigarettes for displaying the number of cigarettes smoked according to an output signal from the cigarette detecting means 1, whereby the number of cigarettes can be displayed so as to promote to quit smoking.