The preferred embodiments described herein provide a Penning discharge plasma source. The magnetic and electric field arrangement, similar to a Penning discharge, effectively traps the electron Hall current in a region between two surfaces. When a substrate (10) is positioned proximal to at least one of the electrodes (11, 12) and is moved relative to the plasma, the substrate (10) is plasma treated, coated or otherwise modified depending upon the process gas used and the process pressure. This confinement arrangement produces dramatic results not resembling known prior art. Using this new source, many applications for PECVD, plasma etching, plasma treating, sputtering or other plasma processes will be substantial improved or made possible. In particular, applications using flexible webs (10) are benefited.