Disclosed in a facsimile apparatus which performs communication using the user-to-user of an ISDN. User-to-user information inputted from a control panel and used when an outgoing call is made is capable of being registered in a buffer memory as one-touch dialing data or abbreviated dialing data, or user-to-user information employed in communication is capable of being registered in the buffer memory as redialing data when communication ends. The user-to-user information is registered as data only with regard to one-touch dialing or abbreviated dialing limited in advance.