A new voltammetric membrane electrode for trace analysis of ozone was developed. The effects of stirring and temperature as well as the response time were investigated. Using a three-electrode voltammetric cell, and a gas permeable membrane, measurements were done using steady-state and pulse techniques. The advantages of the pulse technique in comparison to steady state include a fifty-fold increase in sensitivity, ability to measure in the part per billion range, and less dependence on mixing in the test solution and thickness of the polymeric membrane. The pulse technique is particularly suitable for monitoring applications since the electrode sensitivity is less dependent on the accumulation of suspended matter on the surface of the membrane, when compared to steady-state measurements. One of the main applications of this electrode system will be the control of ozonation processes based on in situ measurement of residual ozone.