A multi-layer structure for packaging formed by at least an inner layer, an outer layer and an intermediate layer, the intermediate layer having an islands-in-a-sea structure comprising a resin A constituting sea portions and a functional resin B constituting island portions, the sea portions occupying not more than 80% of the area of the intermediate layer in cross section, and the inner layer and the outer layer being resins having adhesiveness to said resin A. The adhesion among the layers is improved without providing any particular adhesive layers among the intermediate layer having a function such as gas barrier property and the inner and outer layers, and, besides, transparency is improved.