To eliminate the need of payment in the cash of a visiting country and of dialing operation so as to facilitate international telephone calling by recording in an integrated circuit element the balance record of a telephone charge, the country code of a called subscriber, a domestic area code, and the telephone number of a domestic contact place.

A telephone card uses an IC card which has an integrated circuit element built in its card body and has an IC chip inside, but a magnetic stripe system may be employed for countries using the magnetic stripe system. An international telephone number recorded in the IC chip consists of a 14-digit number including five marks, i.e., a 2- or 3-digit international telephone mark, a 1- or 2-digit country name mark showing the country of a called subscriber, a 2-digit area mark showing a called area in the country of the called subscriber, a 3-digit dial exchange number, and a 4-digit telephone number. The card is only inserted into a reading/writing means 35 of a public telephone 30 and then the specific telephone number of a foreign country is automatically dialed.