The environment around mobile phone handset 10 is judged according to the number of other mobile phone handsets present near mobile phone handset 10 and the registration status of the nearby telephones. Then, the display sequence of function names on a function selection screen is changed according to the environment. As a result, functions deemed likely to be selected by the user based on the environment surrounding mobile phone handset 10 may be displayed at positions where they may be selected with fewer operations. In this way, the number of operations required of the user for selecting any of multiple functions may be reduced.