PURPOSE: To provide the optical recording medium which obviates the deformation of grooves in spite of continuous repetition of recording and erasing by laminating first and second dielectric layers between a substrate and a magneto- optical recording layer and specifying refractive indices and film thicknesses of the first and second dielectric layers.

CONSTITUTION: The first transparent dielectric layer 12 consisting of SiO2, etc., and having 1.4 to 1.7 refractive index approximately equal to the refractive index of a polycarbonate substrate 11 provided with track guide grooves spirally on it. The transparent dielectric layer 13 having the refractive index larger than the refractive index of the layer 12 and ≤80nm film thickness and consisting of ZnS, etc., is formed thereon. The total of the film thickness of the layer 12 and the layer 13 is specified to ≥90nm. A magneto-optical layer 14, an intermediate layer 15 and a reflection layer 16 are then successively formed on the layer 13. As a result, the adiabatic effect between the magneto- optical layer 14 and the substrate 11 is enhanced without impairing the enhancement effect. Then, the temp. rise of the substrate is suppressed and the deformation of the track guides is prevented.