Abstract: A resin frame such as a gasket or seal is injection-molded around the peripheral edges of a glass sheet which are positioned in a mold cavity which is defined between upper and lower molds that are brought together. Portions of the glass sheet which are spaced from the peripheral edges toward the geometric center of the glass sheet are gripped by a pair of resilient seal members mounted on the molds, respectively. A pair of protective walls is mounted on the molds, respectively, and held against surfaces of the resilient seal members which are closer to the mold cavity. The protective walls have respective distal ends spaced by a distance ranging from 0.01 mm to 0.1 mm from surfaces of the glass sheet when the molds are brought together.