A non-thermal atmospheric pressure plasma reactor including a primary dielectric having at least one slit defined therein and a segmented electrode including a plurality of electrode segments. Each electrode segment disposed proximate and in fluid communication with an associated slit. The slit in the dielectric may be formed in any number of ways such as a plurality of slits defined in a substantially planar dielectric plate. Other configurations include a plurality of dielectric segments (e.g., bars, slabs, rings, annular sections) assembled together so that a slit is formed between adjacent dielectric segments. In operation a voltage differential is applied between the segmented electrode and a receiving electrode disposed proximate the primary dielectric to produce a plasma discharge. The plasma discharge is emitted through the slits in the primary dielectric. This inventive plasma discharge device configuration produces a relatively high density non-thermal plasma discharge of relatively large volume yet is relatively easy and inexpensive to manufacture.