There is provided an optical glass suitable for mold pressing having optical constants of a refractive index (nd) within a range from 1.60 to 1.69 and Abbe number (νd) within a range from 35 to 45, having a glass transition point (Tg) within a range from 300° C. to 500° C., being free from devitrification when the optical glass is held at a temperature which is higher by 100° C. than the glass transition point (Tg) for 30 minutes, comprising in mass % on oxide basis: SiO220–less than 40% B2O35–20% Al2O30–5% ZrO2more than 3%–15% Nb2O510–30% MgO + CaO0–less than 5% in which MgO0–less than 5% CaO0–less than 5% SrO0–10% BaO0–10% ZnO0–18% Li2Omore than 5%–15% Na2O1–10% K2O1–10% Sb2O30–1%, and being free from La2O3, TiO2, Ta2O5 and PbO.