A problem of this invention is to satisfy both of securement of visibility of a display unit and suppression of noises at the time of a telephone call etc. using a receiver and a microphone. In a portable terminal apparatus which relates to the invention, a control unit (16) judges whether a handsfree device (20) is connected or not, on the occasion that a telephone call operation is carried out by an operation unit (18) and a voice telephone call operation by a telephone call circuit (11) and a transmission/receiving unit (12) is started, and in case that the handsfree device (20) is not connected, it is judged that a user is making a telephone call by use of a receiver (13) and a microphone (14) in an apparatus main body in such a state that he puts an apparatus casing to his ear part, and at least one of a drive system, drive frequency of a display unit (19) which comprises a liquid crystal display is changed, and a drive operation giving priority over acoustic characteristics is carried out. On one hand, in case that the handsfree device (20) is connected, a drive operation with high picture quality giving priority over optical characteristics of the display unit (19) is carried out without changing the drive system etc.