The invention relates to a device, preferably a collar, for treating areas of human or animal skin or mucous membrane with a cold atmospheric pressure plasma by creating a dielectrically hindered surface discharge, comprising at least one flexible insulating material (1), a flexible high-voltage electrode (2), a flexible dielectric (3), a flexible grounded electrode (4) and a gas supply (7), characterized in that the flexible high-voltage electrode (2) is embedded in the insulating elastomer (3), having the effect of a dielectric, and the grounded electrode (4) is applied to the elastomer surface facing the surface to be treated.