A medium voltage circuit breaker for the use in high pressure environments has a vacuum interrupter with a fixed contact side and a movable contract side with a movable rod, and a drive in pressure tight insulating housing, electrical terminals to the vacuum interrupter integrated into the pressure housing, and a further pressure tight housing attached pressure tightly at the insulating housing at the movable contact side of the vacuum interrupter with the movable rod, and that the inner volume of the insulating pressure tight housing gastightly separated from the inner volume of the further pressure tight housing by a bellow, through which the movable rod is guided through and mechanically coupled to a drive, which is arranged inside the further housing.
