An apparatus for closing containers includes a movable closing head for applying closures to the containers and is arranged in the interior of a sterile chamber of the apparatus and arranged to move in a longitudinal direction (L) of the containers to be closed. At least one wall is provided which delimits the sterile chamber, wherein the closing device is arranged on a carrier which is arranged partially inside the sterile chamber and partially outside the sterile chamber, and extends through the wall and moves in the longitudinal direction (L) relative to the wall. Arranged in the interior of the sterile chamber is a first sealing element which is elastic in the longitudinal direction (L) and which seals off from the sterile chamber a region of the outer periphery of the carrier.