Disclosed herein is a ventilation device including a controller (60) controlling an operational state of the ventilation device so that the ventilation device operates in either a comfortable operation mode in which switching between total heat exchange ventilation and normal ventilation is performed in accordance with a discomfort index (DI) of outdoor air (OA), or an energy-saving operation mode in which switching between the total heat exchange ventilation and the normal ventilation is performed in accordance with a difference between enthalpy (Ho) of the outdoor air (OA) and enthalpy (Hr) of room air (RA).
