A rectifying device is provided in a vehicle. The vehicle includes a wheel, a housing, and a lower arm. The wheel includes a tire and a rim. The housing is provided with a hub bearing that rotatably supports the wheel. The lower arm is swingably coupled to a vehicle-body lower portion and a lower portion of the housing and extends substantially along a vehicle width direction. The rectifying device includes an air-injection member. The air-injection member is provided in front of the wheel, and configured to inject air and form an airflow that flows in an inclined manner with respect to a vehicle front-rear direction in a region at a side of the wheel near the lower arm so that a downstream side of the airflow is at an inner side in the vehicle width direction with respect to an upstream side of the airflow.