Embodiments of the present application relate to an encapsulant film, a method for manufacturing an encapsulant film, an optoelectronic device, and a method for manufacturing an optoelectronic device, and can provide superior adhesive force with a front substrate and a back sheet, and specifically having long-term adhesive and heat resistance properties. Also, the present application can provide the encapsulant which does not have a negative effect on parts, such as optoelectronic elements or wire electrodes encapsulated in the optoelectronic devices, and on a working environment, and which can maintain superior workability and economic feasibility in device manufacturing.