An air conditioner for a vehicle may include a first air conditioner provided on the engine compartment side with respect to a dash panel, and including an intake unit of suctioning internal or external air and blowing same to the vehicle interior side; and a second air conditioner provided on the vehicle interior side with respect to the dash panel, and including a duct for discharging conditioned air to the vehicle interior side. The dash panel has a through hole formed therein, and has an air guide which connects the first air conditioner and the second air conditioner to each other through the through hole.