A silica-titania composite has a BET specific surface area, as determined by BET analysis of a water vapor adsorption isotherm, in the range of 250 m2/g to 500 m2/g and a contact angle with water of 100° or greater. In the water vapor adsorption isotherm, an adsorbed amount at relative pressure P/P0=0.1 is in a range of 65 cm3/g to 120 cm3/g, an adsorbed amount at relative pressure P/P0=0.5 is in a range of 150 cm3/g to 300 cm3/g, and an adsorbed amount at relative pressure P/P0=0.9 is in a range of 350 cm3/g to 500 cm3/g.