NOVELTY - A fixed plasma (P) source (1) faces a carrier (2) holding a substrate (S), moving relative to it (1) in a first direction, i.e. the feed direction. A plasma outlet plate (3) with openings (3') moves in a different, second direction. Its arrangement and motion ensures that plasma is directed towards the substrate surface via the openings. The outlet plate lies between source and carrier and/or is part of the plasma source, being especially a moveable wall section of the plasma source.    USE - A module coating a substrate under atmospheric conditions in the presence of plasma. The module or process is used to modify a substrate surface under atmospheric conditions (claimed). Cited applications include solar wafer coating and etching, application of functional coatings to stainless steel substrates and anti-adhesion coating of printing plates and/or printing rollers.    ADVANTAGE - The module deposits a very uniform layer. In comparison with prior art, the field of application is extended and flexibility of the process is increased, in forming different coatings or layer systems. Distribution of the plasma is improved by moving the openings. The movement exceeds their separation, to further enhance uniformity. The velocity of movement considerably exceeds the feed rate. The comparatively-heavy plasma source remains stationary. This is a considerable advantage because the plate weights only 300 g, whereas the source weighs up to 15 kg.    DETAILED DESCRIPTION - The feed- or first movement, is in translation and/or has components in the direction of advance. Movement in the second direction includes translation and rotary components. Movements at right angles to the feed direction are included. Rectangular movements and/or translation movements back and forth are executed by the plate. There are many outlet openings. The maximum amplitude or stroke of movement in the second direction exceeds the mean spacing between adjacent openings. The mean velocity of motion in the second direction exceeds that in the first direction by preferably up to 1000%. The outlet is a plane plate and/or numbers of outlet openings are formed in it. These are round- or elliptical nozzles. The outlet plate is held in a sliding or rolling-element bearing which is fixed in position, forming part of the source or its wall. The reaction chamber (4) into which the plasma enters, is designed for the substrate carrier to move through it in the first direction. It is screened from the surroundings (U) by a gas curtain between the wall and the outlet plate, or by gas locks. The plasma source is an arc source or a microwave plasma source. AN INDEPENDENT CLAIM IS INCLUDED FOR the corresponding plasma coating module.    DESCRIPTION OF DRAWING(S) - The drawing shows a simplified schematic cross section of the module.    plasma (P)    substrate (S)    surroundings (U)    plasma source (1)    carrier (2)    plasma outlet plate (3)    openings (3')    reaction chamber (4)