To completely eliminate the production of an incoming tine suddenly from a portable terminal or malfunction of a medical treatment equipment due to a radio wave sent from the portable terminal in an installation, where the use of the portable terminal is inhibited by automatically turning off the power of the portable terminal, regardless of a power supply operation content of a user side in the case that the user side carrying the portable terminal enters the installation where the power of the portable terminal should be turned off.

When a user 2 who is carrying a portable terminal 3 passes through an entrance 6 of an installation 4 and enters the inside, the portable terminal 3 receives radio waves sent from a transmitter 5 (a radio wave, including an identification sign to turn off a power of the portable terminal 3) to have the power supply of the portable terminal 3 turned off automatically.