Applicability of alkoxysilyl group was examined for the first time as the anchor moiety of sensitizing dyes for dye-sensitized solar cells by using alkoxysilylazobenzenes. Alkoxysilylazobenzenes adsorbed efficiently onto TiO2 electrodes by the formation of Si-O-Ti bonds, and the electrodes exhibited much higher durability to water and better photovoltaic performance than in the case of a conventional carboxy dye.