A process for detecting any defect in a ceramic body, including the steps of forming an electrically conductive layer in any such defects including fine voids present in the ceramic body, and then detecting presence or absence of the defect by measuring electrical conductivity between two given points shorted by the electrically conductive layer. The electrically conductive layer may be formed by penetrating an electrically conductive liquid into the defect. Alternatively, the electrically conductive layer may be formed by penetrating a penetrable liquid capable of forming the electrically conductive layer by thermal treatment or chemical treatment and thermally or chemically treating same.