An air conditioner is provided, in which a control box is disposed at a boundary between an indoor main body configured to blow indoor air and an outdoor main body configured to blow outdoor air, and the outdoor air may be introduced into the control box. Accordingly, even if it rains, the air conditioner may prevent direct exposure of the control box and/or a heat sink of the control box to rainwater and facilitate heat dissipation of control components disposed in the control box configured to perform inverter control.