A device for monitoring the tightness of a sealing component wherein the monitoring device has a box with a peripheral partition and a cover made of a transparent material is disclosed. The cover is connected to the peripheral partition such that the cover and the peripheral partition are able to define, with a sealing component, an inner chamber, the peripheral partition with an inner peripheral wall having a lower end equipped with an inner peripheral seal intended to be positioned against the sealing component all around the inner chamber, and an outer peripheral wall arranged outside the inner peripheral wall so as to define, between the outer peripheral wall and the inner peripheral wall, an intermediate chamber extending exclusively in the peripheral partition all around the inner chamber.