The invention refers to an arrangement comprising a processing chamber, at least one cover plate (CP. I, CP.r) for the processing chamber, and a holding assembly (BU.1.1, BU.r.1, HF.CP.I, HF.CP.r, Pos.l, Pos.r, Lim.l, Lim.r). The holding assembly (BU.1.1, BU.r.1, HF.CP.I, HF.CP.r, Pos.l, Pos.r, Lim.l, Lim.r) is arranged to hold the cover plate (CP. I, CP.r) at an outer surface of the processing chamber. The invention further refers to a method for operating such an arrangement. The holding arrangement (BU.1.1, BU.r.1, HF.CP.I, HF.CP.r, Pos.l, Pos.r, Lim.l, Lim.r) guides the cover plate (CP. I, CP.r) with respect to the processing chamber from a covering position into an access-enabling position and back from the access-enabling position into the covering position. The cover plate (CP. I, CP.r) in the covering position covers a part of the outer surface of the processing chamber. The distance between the cover plate (CP. I, CP.r) in the access-enabling position and the processing chamber occurs. The cover plate (CP. I, CP.r) is moved from the covering position into the access-enabling position along a curved opening trajectory. This opening trajectory is horizontal or is sloping with respect to the ground.Linvention concerne un agencement comprenant une chambre de traitement, et au moins une plaque couvercle (CP. I, CP.r) pour la chambre de traitement, et un ensemble de soutien (BU.1.1, BU.r.1, HF.CP.I, HF.CP.r, Pos.l, Pos.r, Lim.l, Lim.r). Lensemble de soutien (BU.1.1, BU.r.1, HF.CP.I, HF.CP.r, Pos.l, Pos.r, Lim.l, Lim.r) est agencé pour soutenir la plaque couvercle (CP.I, CP.r) au niveau dune surface extérieure de la chambre de traitement. Linvention concerne de plus une méthode dutilisation dun tel agencement. Lagencement de soutien (BU.1.1, BU.r.1, HF.CP.I, HF.CP.r, Pos.l, Pos.r, Lim.l, Lim.r) guide la plaque couvercle (CP.I, CP.r) par rapport à la chambre de traitement à partir dune position de couverture jusquà la position permettant laccès et inversement de la
