The portable telephone is provided with an antenna serving as both transmitting and receiving antennas, a radio unit composed of a transmitter and a receiver, a display for displaying telephone numbers, an interchanging key for interchanging functional modes, a key-operating unit including numerical keys, and a control unit. A communicative mode related to a telephonic communication and a noncommunicative mode (a mode unrelated to communication) are selected alternately in accordance with an operation of the interchanging key. When the noncommunicative mode is selected, the radio unit stops functioning and a noncommunicative mode indicating lamp lights up to notify persons around the portable telephone that it is functioning in the noncommunicative mode. According to the aforementioned structure, the persons around the portable telephone will permit a user to use it in the noncommunicative mode.