PURPOSE: To eliminate the need of a troublesome special key operation at the time of holding release and to simplify the operation by providing a control means to release a holding condition with the output of a speech recognition means which recognizes 'Hello'.

CONSTITUTION: In a main equipment 1, line wires 21∼2n are stored, and key telephone sets 41∼4m are connected through lines 31∼3m. When the condition change from ON-hook to OFF-hook of the hooking switch HS of the key telephone system is detected, and a voice signal, identical with a voice signal 'Hello' by a special speaker beforehand stored in the RAM of a speech recognition processor 40 during a constant time, is inputted, this identification result is communicated with a CPU 14 through a control part 35, and the holding condition is released. Simultaneously with this, the control part 35 changed over a relay rl and connects a speaking circuit 31 to a speaking line 32.