Abstract: A chamber for use in vacuum plants, particularly for treating or storing workpieces or other objects and/or for passing workpieces or other objects therethrough. At least one wall of the chamber has at least one opening through which the workpieces or objects can be introduced or removed. The opening can be closed by means of a closing member including a sealing member which acts together with a sealing surface. The sealing surface is arranged within the chamber laterally of the opening. A circumferentially closed sealing member arranged on the closing member rests against the sealing surface in the closed position of the closing member. The sealing surface has imaginary straight generatrices which extend parallel to the axis of the opening of the chamber. The sealing surface has at least two sealing surface portion which are lateraly offset from each other relative to the axis of the opening and which are connected to each other at opposite locations.