PURPOSE: To reproduce phase pits in any of different polarization states of reflected light or transmitted light by providing the optical recording medium with a polarization state changing layer and receiving only the pits of the one state.

CONSTITUTION: Spot light LB of reading out light which is the linearly polarized light emitted from a laser diode is condensed into the information recording surface of the optical disk, by which the spot LB is formed on a track T1. The spot is moved on the track T1 by rotation of the disk. Plural pieces of the phase pits P2, P3 exist in the spot LB. The sepn. of the information of the pits P2, P3 is not possible in this state and correct reproduction is not carried out. The correct reproduction is not possible as well if T0', T1', T2' are included within the spot LB. The temp. of the material layer is raised to the Curie temp. Tc or above in the backward region AR of the spot LB by regulating the output of the reading out light. The magnetic domain of the region AR where the pit P2 exists is then dissipated. Consequently, the reproducing light returns to a photodetector side while its polarization state remains the same as the polarization state of the reading out light within the region AR. The information of only the desired phase pits is thus exactly reproduced.