A cellular phone in which a data storage means can be installed while meeting the requirements for a compact and lightweight design, imposed on the cellular phone, different types of batteries are selectively used on the basis that a battery used in the cellular phone is removable. The optical surface having the non-spherical shape includes an effective area and an area outside of the effective area located outside of the effective area. The photocatalyst is a thin film of nanoparticle TiO2 with primary particle size of 0. The property source may also include a value, and a type check may be performed on that value based on the type attribute of the property definition.