A portable telephone that includes a control unit, a memory unit, a wireless communication function unit, an imaging unit, a display unit, an operation unit, a voice input unit, a voice output unit, a battery and a power supply unit. The control unit controls the battery capacity level of the portable telephone, and information regarding the battery capacity is attached to a transmission image and the composite information is transmitted to the call destination. An alarm image stored in the memory is automatically transmitted when a battery capacity decrease alarm occurs. Therefore, the call destination is always capable of knowing the battery capacity of the sending portable telephone and the present invention can prevent the unintentional line disconnection.