A main information area 31 capable of recording an information signal and
a subsidiary information area 32 for recording subsidiary information
that is different from the information signal are divided in one
principal plane direction of a substrate, and an information layer for
recording the information signal in the main information area 31 is
provided also in the subsidiary information area 32, and medium
identification information for distinguishing the medium optically is
recorded in the information layer of the subsidiary information area 32
without changing the shape of the information layer. As a result, the
medium identification information can be recorded in an optical recording
medium 1 stably. In particular, the initialization of a phase change type
optical recording medium and the recording of the medium identification
information can be performed at the same time, so that the production
process can be simplified, and the production costs can be reduced.