Provided is a method for producing a ceramic body, which is capable of preventing the ingress of moisture into a void between a conductor and the ceramic body more effectively in the ceramic body including the conductor therein. Ingress of a supercritical fluid containing an oxide sol precursor is achieved into a void between an internal electrode layer and a ceramic laminate. After that, the oxide sol is turned into a gel, and subjected to a heat treatment, thereby filling the void between the internal electrode layer and the ceramic laminate with an oxide.