Poisonous substances such as dioxin exhausted in waste management have become a problem recently. This paper will examine the processing method that uses supercritical water as a solution. This processing method can resolve to water a safe inorganic substance of waste without exhausting the poisonous substance by using excellent supercritical water for resolution, however there is a problem of corrosion in the stored tank. This research aims to define the rules concerning corrosion by using cellular automata to bring the simulation result and the experiment result of metallic corrosion together to simulate with the tank, and to forecast the limit of usage.