Mobile radio terminal in which letters for a command can be optionally entered and displayed just after power is turned on, instead of entering hidden letters of a security code

摘要

When power is turned on, control unit (100) requests a user to enter a security code on the basis of information of SIM card (51) inserted into a card I/F (50). If the security code entered by the user is an authorized code, the control unit (100) permits the user to use the apparatus such that the apparatus can be utilized. In addition, the control unit (100) urges a display unit (30) to display a security code entered through operation unit (40), as hidden letters, and to display a control command such that the control command can be visually recognized.