Disclosed is a coating liquid for forming an amorphous silica-based coating film having a low dielectric constant of 3.0 or below and low leakage current, and a method for preparing the coating liquid. The coating liquid is a liquid composition comprising (a) silicon compound obtained by hydrolyzing tetraalkyl orthosilicate (TAOS) and alkoxysilane (AS) in the presence of tetraalkyl ammonium hydroxide (TAAOH) and water, or a silicon compound obtained by hydrolyzing or partially hydrolyzing tetraalkyl orthosilicate (TAOS) in the presence of tetraalkyl ammonium hydroxide (TAAOH) and water, mixing the hydrolyzed or partially hydrolyzed product with alkoxysilane (AS) or a hydrolyzed or partially hydrolyzed product thereof, and hydrolyzing all or a portion of the mixture, (b) an organic solvent, and (c) water. The coating liquid is characterized in that a quantity of water contained in the liquid composition is in the range from 30 to 60% by weight.