PURPOSE: To execute tripartite speaking only with the control of a terminal equipment by constituting a terminal equipment of a mixing and select circuit and a control circuit of a holding circuit.

CONSTITUTION: When tripartite speaking is started in a terminal equipment 10, a holding tone circuit 26 operates a switching circuit 24 by the control of a control circuit 31 based on the operation of a holding button 1 to switch the circuit 24 so that the circuit 26 is connected to a codec 22 for speaking. Then, a channel B1 is held and the holding tone is applied to the codec 22. Next, the circuit 31 controls the mode of a mixing and select circuit 21 by a select button 34 and sets 'channel B2 selection' while confirming the display on a display device 35. The channel B2 is used to call the third party by the normal originating operation. When the destination terminal responds, speaking with the third party is possible by the channel B2 through a handset 20, the mixing and select circuit 21, a switching circuit 25, a codec 23 for speaking, a channel selecting circuit 27, and a signal transmission/reception circuit 28. Thus, tripartite speaking is executed only with the control of the terminal equipment.