An air conditioning apparatus comprises an air conditioner provided with an air inlet port opening to a room, a heat exchanger and a blower, a duct box connected to the air conditioner directly or through a duct, a blow-off casing provided on the duct box to project into the room and having an air outlet opening to the room, and a fan disposed on a lower portion of the blow-off casing, wherein a conical partition wall is provided between the air outlet and the fan to diffuse conditioning air in the radial direction while turning into the horizontal direction, a plurality of ring-like louvers are provided in the air outlet into the form of multiple stages, the fan is rotatable forward and backward and includes an outer rotor motor and a plurality of blades fixedly attached to an outer peripheral surface of an outer rotor of the motor, the air outlet and fan are disposed within a recess provided on the ceiling or wall surface, an oscillating mechanism is provided to oscillate the fan or both of the fan and air outlet integrally, and a start/stop switch is provided for starting and stopping the fan in synchronism with the start and stop of a conditioning air generator.