A solar cell comprising: a semiconductor substrate of p-type (201;301) having a light-receiving surface and a non-light-receiving surface, the substrate being a single crystal silicon substrate, a polycrystalline silicon substrate, or a thin-film silicon substrate, and a pn junction (203;303) in the light-receiving surface side of the substrate (201;301); a first passivation layer (205;305) formed on the non-light-receiving surface, the first passivation layer comprising an aluminum oxide film (205a;305a) and another dielectric film (205b;305b), of silicon oxide, silicon carbide, titanium oxide or tin oxide, formed on the aluminum oxide film, wherein the aluminum oxide film has a thickness of up to 40 nm and contacts a p type surface on the non-light-receiving surface of the substrate; a second passivation layer (204;304) made of a dielectric film serving as an antireflective film, of silicon nitride, silicon oxide, silicon carbide or titanium oxide, formed on an n-type surface on the light-receiving surface of the substrate; a first extraction electrode (208;308) of a fired product of a conductive paste containing a metal oxide, printed on the surface of the first passivation layer (205;305); and a second extraction electrode (207;307) of a fired product of said conductive paste containing a metal oxide, printed on the surface of the second passivation layer (204;304); wherein said aluminum oxide film (205a;305a) consists of aluminum oxide amorphous film, the first extraction electrode (208;308) has been formed by firing the conductive paste such that it penetrates through the first passivation layer to make an electrical contact between the first extraction electrode and the p-type surface on the non-light receiving surface of the substrate, and the second extraction electrode (207;307) has been formed by firing the conductive paste such that it penetrates through the second passivation layer to make an electrical contact between the second extraction electrode and the n-type surface on the light-receiving surface of the substrate. a semiconductor substrate of p-type (201;301) having a light-receiving surface and a non-light-receiving surface, the substrate being a single crystal silicon substrate, a polycrystalline silicon substrate, or a thin-film silicon substrate, and a pn junction (203;303) in the light-receiving surface side of the substrate (201;301); a first passivation layer (205;305) formed on the non-light-receiving surface, the first passivation layer comprising an aluminum oxide film (205a;305a) and another dielectric film (205b;305b), of silicon oxide, silicon carbide, titanium oxide or tin oxide, formed on the aluminum oxide film, wherein the aluminum oxide film has a thickness of up to 40 nm and contacts a p type surface on the non-light-receiving surface of the substrate; a second passivation layer (204;304) made of a dielectric film serving as an antireflective film, of silicon nitride, silicon oxide, silicon carbide or titanium oxide, formed on an n-type surface on the light-receiving surface of the substrate; a first extraction electrode (208;308) of a fired product of a conductive paste containing a metal oxide, printed on the surface of the first passivation layer (205;305); and a second extraction electrode (207;307) of a fired product of said conductive paste containing a metal oxide, printed on the surface of the second passivation layer (204;304); wherein said aluminum oxide film (205a;305a) consists of aluminum oxide amorphous film, the first extraction electrode (208;308) has been formed by firing the conductive paste such that it penetrates through the first passivation layer to make an electrical contact between the first extraction electrode and the p-type surface on the non-light receiving surface of the substrate, and the second extraction electrode (207;307) has been formed by firing the conductive paste such that it penetrates through the second passivation layer to make an electrical contact between the second extraction electrode and the n-type surface on the light-receiving surface of the substrate.