A ventilation apparatus includes a housing having an indoor air inlet, an air discharge opening, an outdoor air inlet, and an indoor air outlet; a total heat exchanger located in the housing, an inner space of the housing being partitioned into a space for the total heat exchange element, an outdoor air inlet space, an outdoor air discharge space facing the outdoor air inlet space, an indoor air inlet space, and an indoor air discharge space facing the indoor air inlet space, a bypass duct having a bypass passage configured to bypass the total heat exchange element, the bypass passage communicating with the indoor air inlet space and the indoor air discharge space. Indoor air passes through at least one of the total heat exchanger and the bypass passage according to an operation mode of the ventilation apparatus.