A device for measuring the filling level of a liquid in a container is provided, which uses an ultrasound sensor. The ultrasound sensor is associated with a damping cup with at least one antechamber, and the antechamber has at least one outer ring and one inner ring. The inner ring is arranged within the outer ring and the ceiling of the inner ring has different heights. The ceiling has a lowest point and a highest point. In the area of the ceiling the inner ring is provided with a venting connection with the outer ring. The venting connection between the inner ring and the outer ring is located at the highest point of the inner ring. The ceiling of the outer ring has different heights including a lowest point and a highest point. A vent hole is provided at the highest point of the outer ring.