A method for producing tempered glass is characterized in that after obtaining tempered glass that has a compressive stress layer by subjecting glass for tempering to an ion exchange treatment, the tempered glass is subjected to a heat treatment at a heat treatment temperature that is 300 DEG C or higher but less than (the ion exchange treatment temperature + 10 DEG C) so that the compressive stress value (CS) of the compressive stress layer is 120-1200 MPa.