Manufacturing method of semiconductor device and semiconductor device

Provided is a method for manufacturing a semiconductor device, comprising a step for using an adhesive sheet which can accurately follow and adhere to recesses and projections even in a processing step for a semiconductor device having recesses and projections on the surface, such as a bump-equipped semiconductor chip or a bump-equipped PCB. The manufacturing method does not generate gas escape in high-temperature treatment and does not generate residual glue on the surface of an adherend when the adhesive sheet is peeled off. A method for manufacturing a semiconductor device includes: a protection step of attaching an adhesive sheet having a sheet-like substrate and an adhesive layer formed on the substrate to a bump-attached surface of the semiconductor device; a UV irradiation step in which UV irradiation is performed on the adhesive sheet to cure the adhesive layer; and a peeling step for peeling and removing the adhesive sheet from the surface to which the bumps are attached, the adhesive layer being a c