The technology provides for alignment of forming positions of glazing gaskets formed on both front and rear sides of a glass panel. After the glazing gasket has been formed on the multilayer glass panel, a first distance L1 is measured from the reference member to the glazing gasket. After the multilayer glass panel has been reversed and positioned at the reference position for the glass panel, a second distance L1′ is measured from the reference member to the glazing gasket. An offset amount of the forming position of the glazing gasket on the rear side of the multilayer glass panel is determined from the difference of the first distance L1 and the second distance L1′. An application starting position of the application nozzle when forming the glazing gasket on the rear side of the multilayer glass panel is corrected based on the offset amount.