Abstract: It is an object to provide a high ion conductive solid electrolyte which uses organic and inorganic complex compound having water absorption and water resistance and to provide an electrochemical system using the high ion conductive solid electrolyte. The high ion conductive solid electrolyte is composed of a complex compound including water that has zirconic acid compound and polyvinyl alcohol. An aqueous solution in which zirconium salt or oxyzirconnium salt and polyvinyl alcohol are dissolved is neutralized by alkali. After removing water used as solvent, unnecessary salts are removed from the neutralized solution. The high ion conductive solid electrolyte is obtained which is composed of the complex compound having zirconic acid compound, polyvinyl alcohol, and water. Various electrochemical systems are obtained each of which use the high ion conductive solid electrolyte.