Provided are a substrate for an organic electronic device (OED) and a use thereof. The substrate may have excellent interfacial cohesive property by preventing interlayer delamination between the organic material layer and the inorganic material layer when being applied to manufacture a flexible device including a structure in which an organic material layer and an inorganic material layer are present together. In addition, when the substrate for an OED is used, an OED may have excellent durability and an excellent another required physical property such as light extraction efficiency.