PURPOSE: To construct a closed number network which is expected by a subscriber through the use of a general network even if there is no private line by providing a registration means in which a closed number and a public network number correspond, a translation means and the transmission and reception means of number information in a subscriber house.

CONSTITUTION: With dialling a special number from a telephone set 31 which is accommodated in a PBX30, a line is connected with a closed number network number registration equipment 11, and a closed number network constitution list consisting of the correspondence between the closed number by an additional dial from the telephone set 31 and a public network number is received and accumulated. Furthermore, number translation information in a number translation device 12 is rewritten and the number information transmission and reception equipment 13 is requested to transmit the closed number network constitution list. The number information transmission and reception equipment 13 uses and connects a number information transmission and reception equipment 23 under the control of a PBX40 and a public line 70 in accordance with the closed number network constitution list, transfers the closed number network constitution list. The number information transmission and reception equipment 23 rewrites number translation information in a number translation device 22 in accordance with the closed number network constitution list. Thus, the closed number network can be constructed.