Methyl bromide which is most popular disinfectant of soil has been prohibited from using except for an indispensable use by 2015. Therefore we pay attention to ozone as a substitute of the methyl bromide for soil sterilization, because the ozone is easily generated by dielectric barrier discharges. We have been developing an ozone generation system which is suitable to the soil sterilization and also investigating the soil sterilization with the generated ozone. So we are investigating influences of ozone generation characteristic on the screw electrode ozonizer by changing of outer electrodes, applied voltages, and flow rates of source gases. This time, in order to investigate the influence of the outer electrode form on ozone generation properties, we used two different outer electrodes; the single electrode of 11cm width and 3-divided-electrodes of $1cm{ imes}3$(electrode spaces of 4cm). As results, maximum values of the ozone concentration, the ozone yield and the ozone generation efficiency were obtained when the electrode of 11cm was used for the outer electrode.