To provide an optical recording medium, which is hardly influenced by the degree of thermal conductivity of thermal interfering layers, or protective layers to be formed on both sides of a recording layer or the like, and is excellent in sensitivity and recording speed, allows the contrast after recording to be set larger and, at the same time, is suitable for binary recording.

This optical recording medium is so constituted as to have a recording layer 3 made of the antimony (Sb) oxide base phase separation recording material (Sb2O5-) having the predetermined nonstoichiometric ratio formed on a board 2 and protective layers 4, each of which has a function as the thermal interference layer and protects the recording layer. In addition, the filmy recording layer 3 is formed on the board 2 by RF or DC reactive sputtering.