Abstract: An automatic shot-blasting device for containers, adapted more particularly for automatic sand-blasting and shot-blasting installations. The installation comprises a movable gantry for the shot-blasting of the sides and the roof, a shot-blasting panel for the end, and possibly an internal shot-blasting device. The air-shot mixture is transmitted by a switching device comprising two plates of which one is fixed and the other is movable in rotation and in translation. A step by step device causes the movable plate to rotate in order to bring the nozzles of the two plates into communication and permit the passage of the air-shot mixture therethrough.