Abstract: A closure for a canning glass container with a glass cover and a rubber ring therebetween has an upper rim which is formed in the container and provided with a sealing lip with a wedge having a tip with a radius of curvature between 1 mm and 3 mm, a supporting rim formed in the glass cover and having a circular depression located opposite to the wedge and having a radius of curvature exceeding the radius of curvature of the wedge with the wedge and the circular depression extending over an angle of approximately 110.degree.-70.degree., and a projection formed in the glass cover at its side facing toward the canning glass container and provided with a circular outer edge arranged so that it laterally limits the supporting rim of the canning glass container, centers and holds the rubber ring and centers the glass cover in an inner edge of the canning glass container so that relative displacement of the glass cover and the canning glass container which can hinder closing of the latter, is excluded.