Painting compressed-air treatment chamber (1; 101; 201; 301; 401) for improving the flow properties of compressed air or compressed gas mixtures in the painting process, comprising - a housing (2; 102; 202; 302; 402) for forming a cavity (3; 103; 203; 303; 403), wherein the housing (2; 102; 202; 302; 402) comprises an outer sheath (4; 104; 204; 304; 404) bounding the cavity (3; 103; 203; 303; 403); - at least one air inlet opening (5; 305; 405) and at least one air outlet opening (6; 306; 406), wherein the air inlet opening (5; 305; 405) and the air outlet opening (6; 306; 406) are arranged such that the compressed air or the compressed gas mixture is able to flow through the cavity (3; 103; 203; 303; 403), preferably able to flow through it in a longitudinal direction; - at least one electrode (8, 19; 108, 119; 208, 219; 308; 319) arranged inside the cavity (3; 103; 203; 303; 403); - at least one high-voltage source for supplying a high voltage to the electrode (8, 19; 108, 119; 208, 219; 308; 319; 408, 440) characterized in that - at least one insulation layer (10; 25; 125; 225; 325; 425) is arranged inside the cavity (3; 103; 203; 303; 403) on an inner surface of the outer sheath (4; 104; 204; 304; 404) and - an electromagnetic high-voltage alternating field, preferably an inhomogeneous electromagnetic high-voltage alternating field or a partly inhomogeneous electromagnetic high-voltage alternating field, having an active zone to be flowed through by compressed air to be treated, is able to be generated inside the cavity (3; 103; 203; 303; 403), between the electrode (8, 19; 108, 119; 208, 219; 308; 319; 408, 440) and a counterelectrode (12, 22; 112, 122; 212, 222; 312, 322; 412, 422). - a housing (2; 102; 202; 302; 402) for forming a cavity (3; 103; 203; 303; 403), wherein the housing (2; 102; 202; 302; 402) comprises an outer sheath (4; 104; 204; 304; 404) bounding the cavity (3; 103; 203; 303; 403); - at least one air inlet opening (5; 305; 405) and at least one air outlet opening (6; 306; 406), wherein the air inlet opening (5; 305; 405) and the air outlet opening (6; 306; 406) are arranged such that the compressed air or the compressed gas mixture is able to flow through the cavity (3; 103; 203; 303; 403), preferably able to flow through it in a longitudinal direction; - at least one electrode (8, 19; 108, 119; 208, 219; 308; 319) arranged inside the cavity (3; 103; 203; 303; 403); - at least one high-voltage source for supplying a high voltage to the electrode (8, 19; 108, 119; 208, 219; 308; 319; 408, 440) - at least one insulation layer (10; 25; 125; 225; 325; 425) is arranged inside the cavity (3; 103; 203; 303; 403) on an inner surface of the outer sheath (4; 104; 204; 304; 404) and - an electromagnetic high-voltage alternating field, preferably an inhomogeneous electromagnetic high-voltage alternating field or a partly inhomogeneous electromagnetic high-voltage alternating field, having an active zone to be flowed through by compressed air to be treated, is able to be generated inside the cavity (3; 103; 203; 303; 403), between the electrode (8, 19; 108, 119; 208, 219; 308; 319; 408, 440) and a counterelectrode (12, 22; 112, 122; 212, 222; 312, 322; 412, 422).