Abstract: A device for treating the exterior of an aircraft, more particularly the wing and tail surfaces of an aircraft, comprising two gantries disposed on either side of a parking guide line on an aircraft parking place. The gantries are placed to be moved towards one another in a direction transversely to said parking guide line, from a position in which the gantries are mutually spread corresponding to the wing span of an aircraft. Said gantries are each provided with an elongate support beam that extends substantially parallel to said parking guide line and is provided with means for dispensing a treatment fluid, which means is formed by at least one spraying tube extending longitudinally of the respective beam, said spraying tube is equipped with longitudinally spaced spraying nozzles that cooperate with independently controllable valves.