PURPOSE: To instantly inform a true terminal attribute to the general user of a telephone terminal equipment by displaying the attribute of the telephone terminal equipment operated by the key operation of the telephone terminal equipment having a display device on the display device so as to make the check of the attribute by the user efficient.

CONSTITUTION: A memory device 30 storing the attribute of the telephone terminal equipment accommodated n an automatic exchange is provided. Telephone terminal equipments 50∼52 from one call pickup group as the attribute, and it is assumed as an extension connection restriction class of each terminal equipment that the telephone terminal set is special A subscriber and the telephone terrminal sets 51∼52 are A-subscribers. In desiring the extension connection service class of the terminal set 50 by the user of the telephone set 50, the user dials an attribute display number '19' from the telephone set 50 and dials the extension connection service class number '7' succeedingly, then the information is sent to a central control unit 20 via a line circuit 40 and the central control unit 20 reads the extension connection service class identification number of a memory device 30. Since the extension connection service class identification number of the terminal set 50 is '0', the central control unit 20 applies the display instruction of 'special A' to the display device of the set 50.