The disclosure relates to a metal oxide film formed on a glass substrate by the so-gel process with using a solution of a metal alkoxide. To afford water repellency to the oxide film, a fluoroalkylsilane is mixed with an alkoxysilane solution in the molar ratio of the alkoxysilane to the fluoroalkylsilane ranging from 1:10 to 10:1. Then, the mixed solution is diluted with a solvent such that the total concentration of the alkoxysilane and the fluoroalkylsilane is from 1 to 10 wt % in a diluted solution. Then, water in the amount of 100 mol % to 1000 mol % of the total amounts of the fluoroalkylsilane and the alkoxysilane is added to the diluted solution so as to partially hydrolyze the fluoroalkylsilane and the alkoxysilane, thereby forming a sol. Then, the sol is applied to the glass substrate, and the coated glass substrate is heated so as to form the metal oxide film thereon.