Abstract: Apparatus for treating the surface of a body by corona discharge, the apparatus comprising:a reaction enclosure through which said body to be treated can run along a "through" axis;an electrode raised to a "treatment" potential;a counter-electrode raised to a potential that is lower in absolute value than the potential of said electrode, said counter-electrode surrounding said through axis and said electrode and said counter-electrode together being disposed so as to define a "plasma-generating" zone in the vicinity of said through axis and in which said corona discharge takes place; andat least one passage formed in said enclosure to feed a plasma-generating reagent gas for treatment purposes;wherein said electrode is provided with a plurality of portions having small radius of curvature, i.e.