An optical recording medium includes a) a dielectric layer, b) a recording layer,
and c) a reflective layer, which are stacked on a surface of a substrate in the
described order or stacked on the surface in the order of b) the recording layer,
a) the dielectric layer, and c) the reflective layer. The recording layer contains
a mixed nickel oxides which decomposes to release a gas and becomes transparent
upon heating.