PURPOSE: To avoid the direct touch of a cold wind with the human body when defrosting, by automatically changing the blowoff direction of an indoor unit to the upward direction when defrosting.

CONSTITUTION: Defrosting is commenced by means of inverse cycle operation while a solenoid 10 is conducted, and the solenoid 10 automatically drives a movable damper 8 up to an upward blowoff condition against the force of a spring 11. Consequently, since a heat exchanger 3 in an indoor unit A functions as an evaporator during the operation of defrosting, a cold wind upward blows off as shown in the arrow head Y according to the upward rotation positions of the movable damper 8 even if the cold wind blowoff from a blowoff port 7, thus preventing a bad state of health that the cold with directly touches with the human body of users located under the blowoff port 7.