A crystalline-based silicon photoelectric conversion device comprises: an intrinsic silicon-based layer and a silicon-based layer of a first conductivity type, on one surface of a single-crystal silicon substrate of the first conductivity type; and an intrinsic silicon-based and a silicon-based layer of an opposite conductivity type, in this order on the other surface of the silicon substrate. At least one of forming the intrinsic silicon-based layer of the first conductivity type layer-side forming the intrinsic silicon-based layer of the opposite conductivity type layer-side includes: forming a first intrinsic silicon-based thin-film layer having a thickness of 1-10 nm on the silicon substrate; plasma-treating the silicon substrate in a gas containing mainly hydrogen; and forming a second intrinsic silicon-based thin-film layer on the first intrinsic silicon-based thin-film.