Abstract: A sol-gel method for producing a coating solution for a low reflection film includes: preparing a liquid reaction mixture containing a silicon compound; and allowing the liquid reaction mixture to undergo hydrolysis and condensation in the presence of a solid catalyst so as to form the coating solution. A method for producing a low reflection film includes: preparing a liquid reaction mixture containing a silicon compound; allowing the liquid reaction mixture to undergo hydrolysis and condensation in the presence of a solid catalyst so as to form a coating solution; removing the solid catalyst from the coating solution; applying the coating solution to a substrate; and drying the coating solution on the substrate.