A method for manufacturing a flexible semiconductor device includes (i) forming an insulating film on the upper surface of metal foil, (ii) forming an extraction electrode pattern on the upper surface of the metal foil, (iii) forming a semiconductor layer on the insulating film such that the semiconductor layer is in contact with the extraction electrode pattern, (iv) forming a sealing resin layer on the upper surface of the metal foil such that the sealing resin layer covers the semiconductor layer and the extraction electrode pattern, and (v) forming electrodes by etching the metal foil, the metal foil being used as a support for the insulating film, the extraction electrode pattern, the semiconductor layer, and the sealing resin layer formed in (i) to (iv) and used as a constituent material for the electrodes in (v). The metal foil need not be stripped, and a high-temperature process can be used.