A P2O5—BaO—ZnO—Nb2O5 type optical glass contains 25-50 wt. % P2O5, 15-35 wt. % BaO, 1-25 wt. ZnO, and 3-10 wt. % Nb2O5. The optical glass has a high refractive index (particularly preferably the refractive index nd of 1.6 or more), low dispersion (an Abbe number υd of 42 or more), a low deformation point, and improved resistance to devitrification upon molding, and is suitable for precision-mold press molding or other molding processes and also suitable for transfer of a fine structure.