PURPOSE: To allow the mobile set to be used by a specific user only.

CONSTITUTION: When the user hooks off, a control section 5 allows a display section 10 to display to urge the entry of a password and when the user uses an operation section 1 to enter the password, a collation section 4 collates the entered password with a password latched by a register 2. When the two passwords are coincident, the control section 5 allows a control section 6 to make dialing. That is, after the user enters the password, a destination telephone number is dialed from the operation section 1. The control section 6 receives the telephone number to control a radio interface section 7 and to send the telephone number in a radio wave. When the opposite party replies the call, the user can make talking. On the other hand, when the two passwords are dissident, the control section 5 controls the control section 6 to set the on-hook and even when a destination telephone number is inputted from the operation section 1, the transmission is not implemented.