The invention provides a ceramic separator, which mainly includes a plurality of passive ceramic particles and an ion-conductive material located between the passive ceramic particles. The mass content of the passive ceramic particles is greater than 40% of the total mass of the ceramic separator. The ion-conductive material is mainly composed of a polymer base material which is capable of allowing metal ions to move inside the material, and an additive, which is capable of dissociating metal salts and is served as a plasticizer. The ceramic separator of the present invention has high-temperature stability and high-temperature electrical insulation.