Float glass is formed in tin bath, that is, molten glass continuously flows into tin bath from overflow tank and launder, spreads out on tin surface, and drifts forward under the traction of driving roller. In a certain temperature system, it is flattened and thinned by surface tension and gravity. After cooling, the glass is lifted by the transition roller table, leaves the tin bath, enters the annealing kiln, and then is crosscut, inspected and boxed. Float glass is produced by a special process.