A method for manufacturing a photoelectric conversion device typified by a solar cell, having an excellent photoelectric conversion characteristic with a silicon semiconductor material effectively utilized. The point is that the surface of a single crystal semiconductor layer bonded to a supporting substrate is irradiated with a pulsed laser beam to become rough. The single crystal semiconductor layer is irradiated with the pulsed laser beam in an atmosphere containing an inert gas and oxygen so that the surface thereof is made rough. With the roughness of surface of the single crystal semiconductor layer, light reflection is suppressed so that incident light can be trapped. Accordingly, even when the thickness of the single crystal semiconductor layer is equal to or greater than 0.1 .mu.m and equal to or less than 10 .mu.m, path length of incident light is substantially increased so that the amount of light absorption can be increased.