In the manufacture of a paper container from packaging materials, damage of internal layers of packaging materials is promptly inspected, and degradation by light exposure of content can be prevented. A method of manufacturing light barrier paper packaging materials for liquid food formed from a laminate having a paper layer, a thermoplastic resin outside layer, and a thermoplastic resin inside layer include preparing a substantially completely bleached white bleached paper layer, providing a light barrier layer of light barrier material on the inside of the bleached paper layer before or during lamination of the thermoplastic resin inside layer, and inspecting for defects of the obtained laminate by observation of the visible or invisible inside surface of the bleached paper layer from the thermoplastic resin inside layer side of the obtained laminate through the light barrier layer.