To secure stability of a cellular phone and to facilitate a button operation even in the case of operating the cellular phone with one hand, since a user often performs the button operation with a thumb of one hand in the state of holding the cellular phone with one hand when using it as a communication means by vision such as e-mail or an information gathering means through Internet connection.

In the cellular phone handset, buttons 1-18 as means for operating the cellular phone handset are disposed such that the more frequently used button is arranged at a position closer to the centroid 21 of the cellular phone handset depending on the using frequency of the respective buttons 1-18.