the present invention refers to an apparatus for the plasma treatment of hollow bodies , comprising a vacuum treatment chamber and means for generating the plasma , which apparatus is characterized in that the means for generating the plasma comprise an electrode of a substantially u - shaped cross - section , which is arranged in the vacuum treatment chamber , the hollow bodies immersing at least in part into the u - shaped electrode when the plasma treatment is carried out , and being moved at least temporarily relative to the u - shaped electrode . furthermore , the present invention refers to a method for the plasma treatment of hollow bodies , in which the hollow bodies are moved into a vacuum treatment chamber in which the plasma treatment is carried out and the plasma is generated by an electromagnetic field , which method is characterized in that the hollow bodies immerse at least in part into the electromagnetic field when the plasma treatment is carried out , and that the hollow bodies are moved at least temporarily relative to the electromagnetic field .