To provide a telephone device with a confidential information maintaining function without the need for a user to release a secret mode.

The telephone device 2-1 with the confidential information maintaining function is characterized in including a secret mode automatic release means that detects whether or not a medium 3-1 for storing ID information exists near the telephone device, judges whether or not the ID information is read through wireless communication and whether or not the read ID information is admitted ID information, and automatically releases the secret mode when judging that the medium for storing the ID information exists near the telephone device and the read ID information is the admitted ID information.