Disclosed herein is an air conditioner. The air conditioner includes a housing having an inlet and an outlet, and having a first guide surface forming the outlet and a second guide surface facing the first guide surface provided therein, a heat exchanger configured to heat-exchange air suctioned through the inlet, a blower fan configured to suction air from the inlet, heat-exchange the air by passing air through the heat exchanger, and discharge air toward the outlet, and an airflow control unit provided to be movable between a first position adjacent to one end portion of the outlet from which air is discharged and a second position spaced apart from the end portion of the outlet from which air is discharged, and protruding from the first guide surface or the second guide surface when the airflow control unit placed at the first position.