In order to improve photoelectric conversion properties of a silicon-based thin-film photoelectric converter to which a conductive SiOx layer is inserted to obtain an optical confinement effect, the silicon-based thin-film photoelectric converter according to the present invention includes an i-type photoelectric conversion layer of hydrogenated amorphous silicon or an alloy thereof, an i-type buffer layer made of hydrogenated amorphous silicon, and an n-type Si1-xOx layer (x is 0.25-0.6) stacked successively, wherein the buffer layer has a higher hydrogen concentration at its interface with and as compared with the photoelectric conversion layer and has a thickness of at least 5 nm and at most 50 nm. Accordingly, generation of silicon crystal phase parts and reduction of resistivity are promoted in the n-type Si1-xOx layer, contact resistance at the interface is reduced, and FF of the photoelectric converter is improved, so that the photoelectric converter achieves improved properties.