| 摘要 |
PROBLEM TO BE SOLVED: To provide a portable terminal device that is capable of, when being carried out to the outside of an electric field of radio communication unauthorizedly, deleting security data stored in the portable terminal device.SOLUTION: When an electric field detection part 11 of a control part 1 detects, based on a result of electric field strength detection from a radio part 2, that a portable terminal device 10 moved from the inside of an electric field of radio communication to the outside of the electric field, a power supply control part 12 nullifies an operation for interrupting power supply from a power source of a power supply part 3 to thereby keep the power supply continuing and a timer control part 13 starts a monitoring timer that measures a lapsed time since the movement to the outside of the electric field. Then, when the lapsed time measured by the monitoring timer as a time, in which the portable terminal device 10 continuously exists outside the electric field, exceeds a predetermined certain time, a security data deletion part 14 deletes security data stored in a security data storage part 4. |
