Abstract: Apparatus for the production of glow discharge, preferably for a large-area plasma CVD process, including a vacuum coating chamber (K) and a microwave waveguide resonator with one or more coupling points, wherein the resonator is made in the form of a microwave waveguide ring resonator (13, 13'), reaction zones (R) are formed at the coupling points between the microwave waveguide ring resonator (13, 13') and the vacuum chamber (K), and in each case a series of magnets (5, 5', . . . ; 6, 6', . . . ) of different polarity are provided, so that in front of the reaction zone (R) individual tunnels of magnetic field lines (16, 16') running parallel thereto are formed and each magnetic field (16, 16') encloses a spatially uniform plasma tube (17) in the reaction zone (R).