An air conditioner is provided to prevent dew condensation due to a temperature difference between inside and outside of the cabinet by forming an air layer inside a panel assembly. An air conditioner comprises a discharge panel(200) including a first panel(220) and a second panel(210) coupled to a rear side of the first panel. A discharge port is formed at two sides of the discharge panel. An air layer is formed between the first and second panels. A reinforcing support part(221) for reinforcing the first panel is protruded forward from the first panel to have a stepped structure. A hook(223) and an insertion groove are formed at one and the other of the first and second panels, respectively.
