A ceramic multilayer substrate has a ceramic laminate including a plurality of ceramic layers laminated, having a first main surface, and including internal circuit elements disposed in the inside, a resin layer having a bonding surface in contact with the first main surface of the ceramic laminate and a mounting surface opposite to the bonding surface, external electrodes, each disposed on the mounting surface of the resin layer and electrically connected to at least one of the internal circuit elements of the ceramic laminate, and a ground electrode, a dummy electrode, or capacitor electrodes disposed at an interface between the first main surface of the ceramic laminate and the bonding surface of the resin layer or in the inside of the resin layer.