An optical information recording medium includes a substrate 1 and two information
layers (2, 4) formed on the substrate. The
information layer is formed of a thin film showing a change that can be detected optically by
irradiation of a
light beam 7. A separating layer 3 that is transparent to a
wavelength of the
light beam 7 is formed between the information
layers 2 and 4. Each
information layer (2, 4) includes a sector area having sector address portions (9, 13) and data areas (8, 12) for recording information signals, the sector address portion and the data area being divided in the circumferential direction, and a
management area (10, 14) for recording identification information about the amount of
dislocation between the sector address portions 9 and 14 in the circumferential direction. Thus, the identification information about the amount of
dislocation can be recorded, so that
demodulation errors during
reproduction can be reduced by switching amplification
gain or slice level during
reproduction according to the identification information. Also, stable
data recording can be achieved by switching recording power according to a gate
signal.