Food processing industries are concerned with hygiene management and desire to improve procedures. The most popular sterilizer is hypo-sodium chlorate because it provides excellent sterilization with low cost and is easy to handle. Heat treatment is also good, but there are occasional complaints from customers because the odor of chlorine remains when the package is opened. Chlorine or HCIO etrium is in strong acidic water and it can be used as sterilizer. Odor residue is brief and thus is not a problem.         Semiconductor manufacturing creates pollution and, thus, eliminating pollution is an important task. The objective of semiconductor cleaning is to remove pollutants from semiconductor surfaces. The size of particles to be eliminated is 1/2 ~ 1/10th of the circuit design. As the detailing of semiconductor progresses, surface pollutants affect credibility or yield. Individual cleaning is required to prevent this pollution. The sterilization effect of acidic water may be used to clean semiconductors.         This procedure is used in factories that produce medical or agricultural products as well as beverage manufacturers (soft drinks or beer) and others. Storage tanks become dirty with the accumulation of protein and yeast fungus from soft drinks or beer. Sodium hydroxide or hypo-sodium chlorate was used for the cleaning in the past. Instead of using chemicals, strong acidic water and alkaline water are used. The size of the tank can be up to 100 kiloliters, equivalent to a size of a building. Cleaning at room temperature is possible when an electrolytic solution is used and, thus, additional energy is not needed for heating cleaning water. Moreover, recycling the used cleaning water is under study for addition for energy savings.