This invention relates to a cooling/heating air conditioning device for regulating temperature, which pumps an airflow exhausted from a space in an air conditioning object such as inside of a room or vehicle to the external through the external heat exchanger disposed at the external of the air conditioning object such as outside of the room or vehicle so as to equalize the temperature of the fluid flowing through the internal of the external heat exchanger by means of the temperature difference between the internal and external of the air conditioning object for achieving an energy saving effect.