Abstract: A forced cooling apparatus (1) for use in the production of a tempered glass sheet includes an air-quench unit (9) for blasting cooling air against opposite surfaces of a glass sheet to quench the glass sheet, the glass sheet having been heated at a predetermined temperature, and a contact quenching unit (10) disposed downstream of the air-quench unit and equipped with a water-retentive member wet with water, the contact quenching unit being operative to cause the water-retentive member to contact the opposite surfaces of the glass sheet to further quench the glass sheet. Also disclosed are a tempered glass sheet producing method in which the forced cooling apparatus may be used and a tempered sheet glass which is produced by using a modified form of the contact quenching unit are also disclosed.