A method for manufacturing a semiconductor device provided with a circuit capable of high speed operation while the manufacturing cost is reduced. A method for manufacturing a semiconductor device which includes forming an ion-doped layer at a predetermined depth from a surface of a single-crystal semiconductor substrate and forming a first insulating layer over the single-crystal semiconductor substrate; forming a second insulating layer over part of an insulating substrate and forming a non-single-crystal semiconductor layer over the second insulating layer; bonding the single-crystal semiconductor substrate to a region of the insulating substrate where the second insulating layer is not formed, with the first insulating layer interposed therebetween; and forming a single-crystal semiconductor layer over the insulating substrate by separating the single-crystal semiconductor substrate at the ion-doped layer which acts as a separation surface so that the ion-doped layer is separated from the insulating substrate.