Reinforced glass production method and reinforced glass production apparatus

Provided is a reinforced glass production method that exchanges ions in a glass surface layer, the method comprising: a step for forming, on at least a part of the surface of glass, an ion permeation-inhibiting film that inhibits ion permeation; a first ion-exchange step for exchanging ions by bringing a first molten salt into contact with the surface of the glass on which the ion permeation-inhibiting film has been formed; and a second ion-exchange step for, after the first ion-exchange step, exchanging ions by bringing a second molten salt into contact with the surface of the glass on which the ion permeation-inhibiting film has been formed, the method being characterized in that α < β is satisfied where α is the hydrogen ion concentration index for an aqueous solution that is prepared by mixing the first molten salt with water and has a concentration of 20 mass%, and β is the hydrogen ion concentration index for an aqueous solution that is prepared by mixing the second molten salt with water and has a concentration of 20 mass%.