A glass for chemical strengthening is a glass sheet containing, as expressed by mass percentage based on oxides, 60 to 75% of SiO2, 3 to 12% of Al2O3, 2 to 10% of MgO, 0 to 10% of CaO, 0 to 3% of SrO, 0 to 3% of BaO, 10 to 18% of Na2O, 0 to 8% of K2O, 0 to 3% of ZrO2, 0 to 0.3% of TiO2, 0.005 to 0.2% of Fe2O3, and 0.02 to 0.4% of SO3. The glass has a sheet thickness of 0.2 mm or more and 1.2 mm or less. A value of β-OH measured without polishing both front and back surfaces of the glass sheet is lower than a value of β-OH measured after polishing surface layers of both the front and back surfaces of the glass sheet by 50 μm or more each.