Abstract: Device for carrying out surface treatment on large objects, such as spray-painting of ships. In the prior art, a substantial proportion of the spray mist is deposited elsewhere, which is unwanted. The device proposes an enclosure which is movable along the hull of the ship, from which the spray-painting operation can be carried out through an opening disposed in the enclosure. An air curtain extending to the hull of the ship is present around this opening, through which it is not possible for spray to escape between the enclosure and the ship's hull. An extraction facility for mist is present in the enclosure and supply openings for air are provided. The enclosure consists of a housing which is accessible via a door.