In the present work, the possibility of continuous O- emission using the YSZ was examined. A simple experimental apparatus incorporating a gap between a YSZ (yttria stabilized zirconia) anode and a stainless steel electrode coated with gold was designed and constructed. By applying a DC voltage of 150 V across the electrode gap, the ion current, consisting of negatively charged species such as O- radical anions, could be detected by using the quadrupole mass spectrometer, The results of the variation of ion current with distance between two electrodes have revealed that the emission of O- and electrons are strongly related to the temperature and electric field. From these results, the activation energy of releasing O- from YSZ anode can be described as: E = E-0 - 0.036(V/d) [kJ.mol(-1)]. Furthermore, the electric field may decrease the activation energy of O- desorption from the YSZ anode.