The invention relates to insulation for a container wall element, a container wall of a large container in a thermal plant using such an element and a method for using such a container wall element in a container wall, wherein the container wall element comprises a fireproof material and a thermally insulating material, and an intermediate layer where appropriate. At least one fastening may be introduced into the thermally insulating material. The thermally insulating material can be formed from a glass or metal foam.