An optical disk is provided with a disk substrate having a recording layer
formed on one surface of a substrate and a cover sheet applied over the
recording layer; and a display sheet which is affixed to a surface of the
disk substrate opposite to a surface covered with the cover sheet and
which has substantially the same physical characteristic as that of the
cover sheet. The display sheet and the cover sheet are substantially
brought into coincidence with each other in terms a direction of heat
contraction and a heat contraction rate.