The invention relates to a treatment device for a surface to be treated using a dialectically impeded plasma, comprising a housing (1) which has an end wall (14, 14′) and comprising an electrode (18, 33) which is shielded from the surface to be treated by a dielectricum (19, 34) that forms at least one part at the end wall (14, 14′) and which can be connected to a high-voltage generator (17). The end wall (14, 14′) has at least one spacer (29, 29′) by mamas of which at least one gas chamber is formed when the at least one spacer (29, 29′) rests against the surface to be treated, and the dialectically impeded plasma is formed in the gas chamber for the treatment process. The treatment device simultaneously allows a treatment using the dialectically impeded plasma and the metered supply of a treatment agent in that a storage chamber (25, 25′) which can be filled with a treatment agent is arranged on the end wall (14, 14′) thee facing away from the surface to be treated； the end wall (14, 14′) has passage openings (28, 28′)； and the volume of the storage chamber (25, 25′) can be reduced such that the treatment agent reaches the region of the surface to be treated through the passage opening (28, 28′) when the volume is reduced.
