One surface of a single crystal semiconductor substrate is irradiated with ions to form a damaged region in the single crystal semiconductor substrate. An insulating layer is formed over the one surface of the single crystal semiconductor substrate. A surface of a substrate having an insulating surface and a surface of the insulating layer are disposed in contact with each other to bond the substrate having the insulating surface and the single crystal semiconductor substrate to each other. Heat treatment is performed to divide the single crystal semiconductor substrate along the damaged region and to form a semiconductor layer over the substrate having the insulating surface. One surface of the semiconductor layer is irradiated with light from a flash lamp under conditions where the semiconductor layer is not melted, to repair a defect.