Silica-gel films containing perchloric acid HClO4, dodecatungstophosphoric acid H3PW12O40.29H2O, or tetra-n-buthylammonium perchlorate (n-Bu)4NClO4 were prepared by the sol-gel method using tetraethoxysilane and each dopant. HClO4- and WPA-doped gel films exhibited higher conductivities of 10(-2)-10(-1) S cm-1 at room temperature than the pure silica and (n-Bu)4NClO4-doped gel films (10(-5) S cm-1).