Gas-filled glass plasma electrodes coupled with high-frequency high-voltage generators are used in medicine and dentistry for more than a century. In recent literature, therapeutic effects of such procedure have been explained through topical bio-oxidative effects of ozone generated by the dielectric barrier discharge. The aim of this study was to evaluate characteristics of electric field and optical emission spectrum generated in the treatment field by the glow discharge of the plasma electrode. Emission spectrum in red and near-infrared wavelength range (540-886 nm) and pulsed electric field (impulse frequency 1053 Hz, exponentially damped sine wave in the range of 33 kHz, duty cycle 20%) were recorded. Estimated electric field strength at 1-mm distance was in the range from 5.8 to 13.7 kV/m and between 10 6 and 10 8 V/m in the close proximity of electrode's surface (below 0.01 mm). Recorded factors are integral constituents in the treatment field and their properties can be correlated to the known biological and therapeutic effects of photostimulation and electrostimulation. These factors present important bioactive components which could be responsible for therapeutic effects, reported in number of clinical studies, especially those which could not be explained through topical bio-oxidative effects of ozone.