an automatic call transfer circuit for a plurality of telephones which are connected in parallel respectively between a pair of telephone lines , relay coils each one of which is connected with a different one of the telephones respectively and condensers each one of which is connected in parallel with a different one of the relay coils respectively . energizing of each one of the relay coils makes it possible to use only the telephone which is connected to the energized relay coil . the circuit further comprises a current holding circuit which has at least one zener diode for holding a current between the telephone lines at a moment of call transfer between the telephones in a telephone conversation where the current is flowing in a prescribed single direction .