PROBLEM TO BE SOLVED: To provide an air cleaning device having stable sterilization effect by preventing bacteria from being propagated in a sterilization element.SOLUTION: The air cleaning device includes: a dripping device 18 for delivering sterilization liquid 17 by drops to the sterilization element 16 to impregnate it with the liquid and an immersion tank 19 for storing the sterilization liquid 17. The lower end of the sterilization element 16 is dipped in the sterilization liquid 17 within the immersion tank 19, and the sterilization element 16 sucks the sterilization liquid 17 in the immersion tank 19 by capillarity when it is dried.