To appropriately answer to a visitor by converting data recorded in a non-contact ID card held by the visitor into character data or voice data by utilizing data reading technique of a non-negotiating ID card and confirming the data with an image on which the visitor is reflected and voice on the answerer's side.

This interphone system is constituted so as to provide a visitor reception machine 2 consisting of an exterior photographing means 4 and a voice input/output means 5 and an answering machine 3 consisting of a voice input/output means 8 by which transmission/reception of voice data is possible between the means 8 and the voice input/output means 5 of the visitor reception machine 2 and an image display means 7 for receiving and displaying image data from the exterior photographing means 4, the visitor reception machine 2 has a reading means 12 for reading visitor identification data recorded in the non-contact ID card 11 by which transmission/reception of the data at a non-contact state is possible at the non-contact state and transmitting the read visitor identification data to the answering machine 3, the visitor identification data in the non-contact ID card 11 held by the visitor are read by the reading means 12 and displayed by the image display means 7 of the answering machine 3.