PURPOSE: To improve an apparent heat exchanging efficiency of an entire heat exchange type ventilator and to provide means for preventing condensation at a heat exchanging element in a cold temperature area.

CONSTITUTION: The heat exchange type ventilator comprises a suction air temperature sensor So for sensing a suction air temperature after heat exchanging, an indoor air temperature sensor Si for sensing an exhaust air temperature before heat exchanging, and an electric heater H for heating the suction air before the heat exchanging, wherein, when the atmospheric temperature is lower than a predetermined value, the suction air is heated by the heater H based on detection signals of both the sensors Si, So to substantially equalize it to the indoor temperature.