PROBLEM TO BE SOLVED: To provide a ventilation device for purifying indoor air without being affected by seasons or weather. SOLUTION: In a ventilation device, a purification duct 12 that is composed of a transparent material while being provided indoors is extended to an area below the floor, at the same time a plant-planting part 16 for planting a plant 17 with an air purification operation is provided in the purification duct 12, and an upper exhaust fan 20 for blowing air through the inside of the duct from the purification duct 12 to the indoor side is provided.
