Technologies that prevent housing equipments from the deposition of stains have been developed in our company. Among them, a new technology to prevent a toilet bowl from stains is introduced in this report. The toilet bowl is soiled with two types of stains. The one is the inorganic scale that covers to the dried surface of the toilet bowl, and the other is the organic slime that covers the surface soaked in water. Because the inorganic scale is considered to be caused by adhesion of the silicate in tap water, it could be prevented by coating organic molecule on the bowl surface. On the other side, the organic scale that is considered to be caused by the propagation of bacteria could be solved by antibacterial technology. In this way, different problems of deposited stains must be prevented by different approaches.