A ceramic joined body includes: a pair of ceramic plates; an electrode layer that is interposed between the pair of ceramic plates; and a joining layer that is disposed in a periphery of the electrode layer between the pair of ceramic plates, in which at least one of the pair of ceramic plates and the joining layer is formed of a composite of an insulating material and a conductive material, a gap is provided between an outer edge of the electrode layer and an inner edge of the joining layer, and a content ratio of the conductive material in the at least one of the pair of ceramic plates and the joining layer is 3% by mass or more and 12% by mass or less.