A glass substrate for a display, which is formed of a glass having a light weight and having high refinability with decreasing environmental burdens, the glass comprising, by mass %, 50 to 70% of SiO2, 5 to 18% of B2O3, 10 to 25% of Al2O3, 0 to 10% of MgO, 0 to 20% of CaO, 0 to 20% of SrO, 0 to 10% of BaO, 5 to 20% of RO (in which R is at least one member selected from the group consisting of Mg, Ca, Sr and Ba), and over 0.20% but not more than 2.0% of R′2O (in which R′ is at least one member selected from the group consisting of Li, Na and K), and containing, by mass %, 0.05 to 1.5% of oxide of metal that changes in valence number in a molten glass, and substantially containing none of As2O3, Sb2O3 and PbO.