PURPOSE: To eliminate a trouble of substituting response of a parson around an extension telephone set and the transmission of destination information by answering automatically to an incoming call to the extension where the subscriber is absent and displaying audibly or visually the destination of the callee for the caller in the case the extension subscriber goes out after registering the destination.

CONSTITUTION: When a call comes in from a multifunctional telephone set MFT 11 or an external trunk 31, a call detection part 52 detects the call, then receives a dial information. A dial information reader part 53 reads the extension number of the callee from this dial information, collates the content in a corresponding address in an extension subscriber destination memory circuit 62, and decides the destination of the callee subscriber is registered. However, if the call is from an MFT at an extension instead of from an external line, the destination information is transmitted through an ordinary telephone set TEL 12 from a terminal control part 51 to the MFT 11, so that the destination information is displayed on the displayer of the MFT 11. Thereafter, under the control of a connection control part 54, a voice massage transmission circuit 30 and the MFT 11 are connected with each other, and a voice message is transmitted to the caller side. As a result, a trouble of substituting response of a person and the transmission of destination information of the callee can be eliminated.