In an air conditioning apparatus for a vehicle, a blower unit is arranged such that air is discharged in a substantially front and rear direction of the vehicle. An evaporator is opposed to an air discharge port of the blower unit and inclined at an angle equal to or greater than 45 degrees with respect to a horizontal plane. The heater core is arranged horizontally above the blower unit and an end of the heater core is adjacent to an upper end of the evaporator. Further, a slide door is provided downstream of the air discharge port to distribute the air toward the evaporator and the heater core. By this arrangement, dimensions of the air conditioning apparatus are reduced with respect to horizontal and vertical directions. Thus, this compact air conditioning apparatus can be installed in a small space such as in a center console or an interior side trim space.