A communication terminal apparatus which improves the a quality of an additional function such as image processing, music reproduction etc. over repressing power consumption is provided. The communication terminal apparatus has a transmission and reception unit adapted to transmit or receive a signal including a voice signal or an image signal, a decode processing unit adapted to decode a received signal, a first control circuit for controlling the transmission and reception unit and the decode processing unit, a second control circuit for processing an image signal which is outputted from the decode processing unit, a first power supply unit adapted to supply electric power to the first control circuit, and a second power supply unit adapted to supply electric power to the second control circuit, and in case that the communication terminal apparatus is not operated for a given length of time, the second power supply unit reduces electric power to the second control circuit.