A device for protection of an optical sensor includes at least one nozzle for projection of air in front of the optical sensor, the projection nozzle being arranged on a side of the optical sensor and linked to an air discharge pump via a discharge conduit such that the air projected by the air projection nozzle is flush with the optical sensor, and at least one suction conduit arranged on the opposite side of the optical sensor to the projection nozzle. The suction conduit is linked to the discharge conduit of the pump, downstream of the pump, such that the suction in the suction conduit is achieved by a Venturi effect.