An air conditioner includes: an air blower configured to take air from an inlet, and to blow the air from an outlet; a filter configured to purify the air; a first chamber and a second chamber taking the air purified by the filter; a humidification filter provided in the second chamber, and humidifying the air taken into the second chamber; and a divider opening and closing an opening that provides communication between the first chamber and the second chamber, and adjusting a volume of the air taken from the first chamber into the second chamber. The air taken from the first chamber into the second chamber and/or the air taken into the second chamber is blown from the outlet.