Ag thin films are easily corroded in wet atmosphere, and their durability needs to be improved. We introduced 3-mercaptopropyltrimethoxysilane (MPTMS) and 1-dodecanethiol (1-DT) on the surface of 10 nm thick Ag thin films and only MPTMS at the interface of Ag thin film and glass substrate. We investigated the durability of the Ag films after an environmental test at 40 °C and 90 RH%. The surface roughness, sheet resistance, and optical transmittance of the as-fabricated Ag films showed less change than that of single-layer Ag films. As a result, the organic monolayers protect the Ag thin film and the 1-DT surface layer protects the Ag film better than MPTMS, and the optimum configuration was that of 1-DT/Ag/MPTMS/glass.