Underwater plasma is formed from a tungsten electrode inserted in a narrow dielectric capillary. Plasma is formed by electrical breakdown. It is produced with atomic oxygen, atomic hydrogen, and hydroxyl ion by the dissociation of vapor. It is also formed of chemical agents like chlorine gas, hypochlorousacid, hypochloriteion and free available chlorine, which are useful sterilization substances. The energy yield was decreased by injecting the gas (N2, Ar, and O2) into a electrode. In this context, the plasma is formed from a electrode by approximately 55% energy levels.