In a thin film photoelectric conversion device fabricated by addition of a catalyst element with the use of a solid phase growth method, defects such as a short circuit or leakage of current are suppressed. A catalyst material which promotes crystallization of silicon is selectively added to a second silicon semiconductor layer formed over a first silicon semiconductor layer having one conductivity type, the second silicon semiconductor layer is partly crystallized by a heat treatment, a third silicon semiconductor layer having a conductivity type opposite to the one conductivity type is stacked, and element isolation is performed at a region in the second silicon semiconductor layer to which a catalyst material is not added, so that a left catalyst material is prevented from being diffused again, and defects such as a short circuit or leakage of current are suppressed.