A new outside mirror which enhances rearward visibility on a rainy day has been developed using a TiO2–SiO2 coating on the glass base. Prepared by the sol–gel process, the coating spreads out rain droplets on the mirror surface into a thin film of water by a photocatalytic hydrophilic effect in the TiO2–SiO2. This mirror maintains its good hydrophilicity for a long time, and when hydrophobic contaminations collect on the glass surface, the sun's radiation induces a photocatalytic effect that serves to decompose the contaminations. Furthermore, the new mirror has sufficiently high durability for use in the severe automotive environment.