A process for producing a web-like laminate material for packaging container composed of a base layer and a thermally sealable inner layer, comprising: introducing an oxygen-containing gas in a silver vapor atmosphere; carrying a web-like base film in the silver vapor atmosphere to form a thin film of metallic silver on a surface of the web-like base film; oxidizing the thin film into a thin film of silver oxide; drawing out the base film provided with the thin film of silver oxide from the silver vapor atmosphere to obtain a web-like base layer; laminating an inner face of the web-like base layer with a thermally sealable inner layer, printing a container design on an outer face of the web-like base layer; and forming a thermoplastic layer or a support layer on the outer face and inner face of the web-like base layer. A seal zone, vicinity thereof and entirety of the container can be formed in an antibacterial atmosphere or with an antibacterial material.