PURPOSE: To attain speech recording and reproduction of a digital telephone set by providing a digital conference device for plural parties, a sound recording device, an information reception means and a control means to the system.

CONSTITUTION: A time division type automatic telephone exchange 2 is provided with a digital conference device 25 for plural parties and a digital sound recording device 26. Then recording request information is received from digital telephone sets 1-1, 1-2 during talking, the digital telephone sets 1-1, 1-2 during talking are connected to the digital conference device 25 for plural parties according to the received recording request information and the digital sound recording device 26 are connected to the digital conference device 25 for plural parties and the content of speech is recorded. Thus, the recorded content of speech is managed unifiedly not only by a subscriber but also by an automatic telephone exchange side without provision of a telephone set with a recording function or an expensive large capacity long time recording device different from a conventional system, and the speech recording and reproduction of the digital telephone set is attained.