Information recording medium and manufacturing method thereof

摘要

An information recording medium includes a transparent substrate (1) and a recording layer (3) or a metal layer (4) provided on the transparent substrate directly or via a ground layer (6). The information recording medium has a RAM area (11b) on which information is recorded, reproduced or erased, and a ROM area (11a) from which only reproduction is made, and an average thickness of the recording layer of said RAM area is larger than that of the recording layer or metal layer of the ROM area.