Method for manufacturing semiconductor device

Suppression of generation of a stripe pattern (unevenness) when an SOI substrate is manufactured by a glass substrate and a single crystal semiconductor substrate bonded to each other. A single crystal semiconductor substrate is irradiated with ions so that a fragile region is formed in the single crystal semiconductor substrate; a depression or a projection is formed in a region of a surface of an insulating layer provided on the single crystal semiconductor substrate, the region corresponding to the periphery of the single crystal semiconductor substrate; the single crystal semiconductor substrate is bonded to a base substrate; thermal treatment is performed thereon to separate the single crystal semiconductor substrate at the fragile region, so that a single crystal semiconductor layer is formed over the base substrate; and the single crystal semiconductor layer in the region corresponding to the periphery is removed.