The present invention provides float glass for chemical strengthening which enables warping after chemical strengthening to be effectively minimized, and enables polishing etc. prior to chemical strengthening to be omitted or simplified. The float glass is provided with a bottom surface that comes into contact with molten metal during casting, and a top surface that is opposite to the bottom surface. The absolute value of the difference between the standardized hydrogen concentration at a depth of 5 to 10 [mu]m for the top surface and the bottom surface is not more than 0.35. The ratio of the average H/Si strength at a depth of 5 to 10 [mu]m for the bottom surface with respect to the top surface is not more than 1.65, and the ratio of beta-OH in the surface layer at a depth of 5 to 30 [mu]m for the bottom surface with respect to the top surface is not more than 1.27.