A surface of a single crystal semiconductor substrate is irradiated with ions to form a damaged region, an insulating layer is formed over the surface of the single crystal semiconductor substrate, and a surface of a substrate having an insulating surface is made to be in contact with a surface of the insulating layer to bond the substrate having an insulating surface to the single crystal semiconductor substrate. Then, the single crystal semiconductor substrate is separated at the damaged region by performing heat treatment to form a single crystal semiconductor layer over the substrate having an insulating surface, and the single crystal semiconductor layer is patterned to form a plurality of island-shaped semiconductor layers. One of the island-shaped semiconductor layers is irradiated with a laser beam which is shaped to entirely cover the island-shaped semiconductor layer.