Abstract: An air conditioner for the air conditioning of the passenger compartment of a vehicle of the type provided with an internal combustion engine and with a tank adapted to contain a fuel for supplying the engine, includes an absorption refrigeration unit. The absorption refrigeration unit includes a refrigeration circuit adapted to contain a fluid compound and has at least one evaporator arranged in thermal communication with the passenger compartment of the vehicle, and a burner supplied by the fuel contained in the tank of the vehicle, arranged in thermal communication with the refrigeration circuit and configured to heat the fluid compound so as to cause the evaporation of at least part of it by making it circulate in the refrigeration circuit toward the evaporator.