To regularly precisely perform an expiration date judgment for content information by preventing the judgment of a regeneration expiration date in the state where a precise standard time cannot be acquired.

Prior to the judgment of the regeneration expiration date of the content information, it is judged whether the clocking of a system clock 22 is valid or invalid, and when it is valid, the judgment of the regeneration expiration date is performed on the basis of the clocking of the system clock 22. When it is confirmed that the clocking is within the regeneration expiration date by this judgment, the content information is read from a storage part 13 and regenerated. When the clocking of the system clock 22 is invalid, and when the content information is out of the regeneration expiration date, the regeneration of the content information is not performed, and a message of this effect is generated and displayed on a display part 15.