Disclosed herein is an air conditioner. The air conditioner includes a housing having an inlet and an outlet, a blade having a plurality of discharge holes and provided to discharge air through the plurality of discharge holes, a first opening formed between one side of the blade near the inlet and the housing when the blade discharges air through the plurality of discharge holes, and a second opening formed between the housing and the other side opposite to the one side of the blade when the blade discharges air through the plurality of discharge holes.