An apparatus and method for polishing and strengthening a substrate are disclosed. In one aspect, the apparatus includes a table on which a substrate is placed, a powder supply portion for polishing a surface of the substrate, a substance supply portion, and an injector. The powder supply portion is placed over the table. The substance supply portion is configured to supply a substance onto the polished surface of the substrate. The injector is configured to inject the powder from the powder supply portion onto the surface of the substrate and the substance from the substance supply portion onto the polished surface of the substrate.