To provide a technique to restrain the recording film of a phase change type optical recording medium from being deteriorated earlier, enhance the reliability of the optical recording medium while avoiding deteriorating the transfer rate and enable the recording density of the optical recording medium to be higher.

When information is recorded on the phase change type optical recording medium, a judgement signal, which is used for judging the deterioration with time, of an amorphous part 1 and a judgement signal of a crystal part 2 are successively recorded along the track direction. When information is overwritten on it, the deterioration with time is judged by comparing the intensity of the light reflected on the crystal part 2 with the reference intensity while referring to the judgement signal.