A condensation product having a high epoxy group residual ratio is obtained by accelerating, with use of neither an acid catalyst nor a base catalyst, hydrolysis and condensation reaction of a silyl group in a silane compound containing an epoxy structure-containing group. Then, a cured product is formed, which has high abrasion resistance, high chemical resistance and low cure shrinkage. The condensation product is synthesized from silane compounds at a specific ratio in the presence of a neutral salt catalyst, which silane compounds are represented by General Formula (I) and General Formula (II), respectively, and then cured with use of a curing agent which cures an epoxy group.