To make possible data transfer of stored contents from one to the other between two portable telephone sets in a short time with a simple operation by providing a transmission converting means that emits a voice signal from a speaker and a reception converting means which converts the voice signal inputted from a microphone into storage data and stores it to a storing means.

A user makes the speaker 3 of a transmitting side unit 1 positioned close to the microphone 4 of a receiving side unit 2 and instructs the execution of data transmission from the operating part of the unit 1. A controlling part 9 stops normal communication according to the instruction and sends the data of a compacted dial stored in a storing part 7 to a transmission converting part 5. The part 5 converts the received data into a voice signal in a prescribed format and transmits it from the speaker 3. The unit 2 catches voice of data issued from the unit 1 from voice coming into the microphone 4 and starts reception. A reception converting part 6 decodes a received voice signal, rearranges it as digital data and stores it in a storing part 8.