A vacuum chamber for performing a plasma treatment comprising a plasma treatment area which is enclosed by chamber walls, and a plasma source comprising: at least one cathode (110, 210, 220, 310, 320, 330, 450) arranged in the vacuum chamber (100, 200, 300, 400) for cathodic vacuum arc evaporation with an arc anode which is connected to the vacuum chamber (100, 200, 300, 400); a shield (115, 230, 332, 333, 334) which can be arranged in front of the cathode; at least one electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) arranged in the vacuum chamber (100, 200, 300, 400), wherein the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) comprises a working surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450); and the working surface is a two-dimensional surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450), and the two-dimensional surface has a first orthogonal extension and a second orthogonal extension to a surface normal, wherein the first orthogonal extension is perpendicular to the second orthogonal extension, characterized in that a length ratio of the first orthogonal extension to the second orthogonal extension is between 0.1 and 1; and at least one magnet (301, 302, 480, 490) for generating a magnetic field which acts on the working surface of the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) is arranged in, on or in and on the vacuum chamber (100, 200, 300, 400), wherein the magnet (301, 302, 480, 490) comprises a front-side magnet and / or a rear-side magnet (301, 480, 490), wherein the front-side magnet is arranged in the area of the working surface for generating a front-side magnetic field and the rear-side magnet (301, 480, 490) is arranged behind the working surface for generating a rear-side magnetic field. at least one cathode (110, 210, 220, 310, 320, 330, 450) arranged in the vacuum chamber (100, 200, 300, 400) for cathodic vacuum arc evaporation with an arc anode which is connected to the vacuum chamber (100, 200, 300, 400); a shield (115, 230, 332, 333, 334) which can be arranged in front of the cathode; at least one electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) arranged in the vacuum chamber (100, 200, 300, 400), wherein the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) comprises a working surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450); and the working surface is a two-dimensional surface for collecting the electrons emitted from the cathode (110, 210, 220, 310, 320, 330, 450), and the two-dimensional surface has a first orthogonal extension and a second orthogonal extension to a surface normal, wherein the first orthogonal extension is perpendicular to the second orthogonal extension, characterized in that a length ratio of the first orthogonal extension to the second orthogonal extension is between 0.1 and 1; and at least one magnet (301, 302, 480, 490) for generating a magnetic field which acts on the working surface of the electrode (30, 120, 120a, 130, 140, 240, 250, 340, 350, 360, 460, 470) is arranged in, on or in and on the vacuum chamber (100, 200, 300, 400), wherein the magnet (301, 302, 480, 490) comprises a front-side magnet and / or a rear-side magnet (301, 480, 490), wherein the front-side magnet is arranged in the area of the working surface for generating a front-side magnetic field and the rear-side magnet (301, 480, 490) is arranged behind the working surface for generating a rear-side magnetic field.