A photoelectric conversion device which is excellent in photoelectric conversion characteristics is provided by effectively utilizing silicon semiconductor materials. The present invention relates to a method for manufacturing a photoelectric conversion device using a solar cell, in which a plurality of single crystal semiconductor substrates in each of which a damaged layer is formed at a predetermined depth is arranged over a supporting substrate having an insulating surface; a surface layer part of the single crystal semiconductor substrate is separated thinly using the damaged layer as a boundary so as to form a single crystal semiconductor layer over one surface of the supporting substrate; and the single crystal semiconductor layer is irradiated with a laser beam from a surface side which is exposed by separation of the single crystal semiconductor layer to planarize the surface of the single crystal semiconductor layer.