To provide a private automatic branch exchange, with which a caller can discriminate whether or not the caller agrees with transfer of its call in the case that the private automatic branch exchange receives an incoming call from the caller when an absence transfer mode is set.

The private automatic branch exchange is provided with a transfer destination information table 107 that stores transfer destination information, such as telephone numbers of transfer destinations of all extension telephone sets to which an absence transfer mode is set, an OGM transmission means 108 that transmits an OGM to a caller extension telephone set, and an LCD display means 109 that displays a transfer destination telephone number to which the incoming call received by a called extension telephone set is transferred on an LCD of the caller extension telephone set. When an extension telephone set 102 set to the absence transfer mode receives an incoming call, the telephone set 102 sends an OGM to the caller extension telephone set 101. When the caller determines whether or not the caller agrees with transfer of its call addressed to the extension telephone set 102 to other extension telephone set, the private automatic branch exchange retrieves a transfer destination table 107 for acquiring a transfer destination telephone number of the call addressed to the extension telephone set 102, displays the telephone number of the transfer destination of the received incoming call on the LCD of the caller extension telephone set 101 to indicate explicitly the transfer destination of the caller.