PURPOSE: To obtain image recording device, which does not require assistance, and is free form lacking of recording information and rich in reliability, by a method wherein decision of deteriorated life of a reversible recording medium is performed by detecting record density of its reversible recording medium itself.

CONSTITUTION: Since the title device is provided with a thermal head 405, an erasing heater 404, an infrared reflection sensor 401 of a detecting device and a movable paper guide 403 of a conveying route changing device on a downstream of the infrared reflection sensor 401, a reversible recording medium which has served its life time is detected beforehand and recovered.