To provide a method of efficiently manufacturing a coating composition for forming a high dielectric thin film in which improvement in uniformity of a coating film caused by further increase in wettability, flatness of a film surface caused by adequate viscosity, handling properties caused by adequate drying speed, and productivity for increasing the film thickness caused by the increase in wettability and viscosity is achieved, and furthermore, in which the dielectric thin film generating no crack, reducing the shrinkage of the film, and having excellent dielectric characteristics can be formed.

This manufacturing method comprises: a process for preparing an organic acid salt solution (A) of an alkaline earth metal element using a specific mixed solvent in a specific condition; a process for preparing an alkoxide solution (B) of at least one kind of element selected from the group consisting of titanium, tin, and zirconium using the specific mixed solvent in the specific condition; a process for synthesizing a composite organic acid salt solution (C) using the organic acid salt solution (A) and the alkoxide solution (B) in the specific condition; and a process for adjusting the metal concentration using a diluted solution with a specific composition.