To provide a connection time notifying device for telephone which can give an alarm sound to at least one telephone caller through a telephone line when a call duration is long and the time set by the user is elapsed and a telephone set equipped with the call duration notifying device.

The call duration notifying device is connected to the telephone line 12 and composed of a control part 28 having a timer which starts clocking the time with a connection start signal, an alarm sound supply circuit 30 which gives the alarm sound to at least one of a calling and a called subscriber through the telephone line 12, and a time setting part which is connected to the control part 28; and the alarm sound supply circuit 30 is driven when the set time has elapsed after the connection start signal is sent. Further, the call duration notifying device is connected to the telephone set.