An air conditioning apparatus for a vehicle includes an air conditioning case for forming an air passage through which air is blown into a passenger compartment. In the air conditioning apparatus, during a cooling mode for cooling a passenger compartment, an inside/outside air introduction mode is switched from an inside/outside air-mixing mode where both inside air and outside air are introduced into the air conditioning case to an entire outside air mode where only outside air is introduced into the air conditioning case, when an engine of the vehicle is stopped and the cooling load is smaller than a predetermined cooling load. Therefore, air-suction noise from an inside air introduction port is not caused, and the air-suction noise is not noted by a passenger in the passenger compartment even when the engine is stopped. Thus, noise of the air conditioning apparatus in the passenger compartment can be reduced.