A door for sealing an opening (2) in a wall (3) of a vacuum chamber (4) relative to the atmosphere includes a sealing element (1), which is attached to at least one rod (9, 9′, 9″) and which can be moved between an open position, in which the sealing element releases the opening (2), an intermediate position, in which the sealing element covers the opening (2) but is raised from a seat (7) surrounding the opening (2), and a closed position, in which the sealing element is pressed against the seat (7), a door body (10), which carries the at least one rod (9, 9′, 9″) and the sealing element (1) and which can be tilted about a tilt axis (20) relative to the wall (3) in order to move the sealing element (1) between the intermediate position and the closed position, and at least one tilting actuator (25, 25′, 26, 26′), which has an inner cavity (27) into which a compressed gas can be introduced in order to tilt the door element (10) about the tilt axis (20). At least one wall (39) of the tilting actuator (25, 25′, 26, 26′) bounding the inner cavity (27) is elastic and/or flexible at least over a section of the extent of the wall.