An air conditioner includes a housing comprising an external panel defining an external appearance and having an opening formed at the external panel; a heat exchanger configured to exchange heat with air flowing into the housing; and an air discharge unit configured to discharge air heat-exchanged by the heat exchanger out of the housing. The air discharge unit includes a first discharge unit connected to the opening and discharging air; and a second discharge unit provided at the external panel and discharging air. A method of blowing heat-exchanged air may be changed in accordance with an environment of a user.