Abstract The polarity effect of microdischarge and the characteristics of ozone generation were studied using electrical and optical methods, paying attention to the distribution of microdischarges in terms of time and space and the effect of dielectric surface on microdischarge. As a result, the phenomenon in which a chain of microdischarges occurs in a brief period of time could be observed for the first time. In addition, it was found that the microdischarge characteristic, collective microdischarge phenomenon, and ozone yield vary according to the surface condition of the dielectric electrode used. The ozone yield was high with a glass surface and low with a ceramic surface.