To provide an easy-to-manufacture, high-quality photovoltaic conversion device and an optical power generator and also to provide a manufacturing method with high production efficiency.To realize these, a photovoltaic conversion device is manufactured by a manufacturing method of a photovoltaic conversion device comprising steps of: (1) joining a lot of semiconductor particles 10 to a substrate 1; (2) forming a protective film 6 comprised of an oxide film, nitriding film, or oxynitriding film of a semiconductor constituting the semiconductor particle 10 on the surface of the semiconductor particle 10 except the junction where the semiconductor article 10 is joined to the substrate1; (3) forming an insulator 4 in a lower part between the adjoining semiconductor particles 10 on the substrate 1; (4) removing an upper part of the protective film 6 to allow an upper part of the semiconductor particle 10 to be exposed; and (5) forming an upper electrode 5 on the surface of the exposed upper part (connection area S) of the semiconductor particle 10 and the surface of the insulator 4.