Abstract: A vent device has: a vent duct having a vent opening for communicating between the inside of the vehicle and the outside of the vehicle; and a flap attached to the vent duct and being able to open and close the vent opening. In the vent device, an electromagnet is disposed in a lower section of a peripheral edge of the vent opening in the vent duct, and an iron plate is disposed in a lower section of the flap. These electromagnet and iron plate constitute a suppression mechanism. In the vent device, when a possibility that a vehicle door is opened or closed is low, the electromagnet is brought into an energized state by a controller, and opening of the vent opening is suppressed. When the possibility that the vehicle door is opened or closed is high, the electromagnet is brought into an unenergized state by the controller.