A ceramic package (1a; 1b; 1c; 1d) for filling with a liquid-containing electrolyte, comprising: a package body having opposite front and back surfaces (3, 4) and defining therein a recessed cavity open at the front surface of the package body to be filled with the liquid-containing electrolyte, the package body comprising a plurality of ceramic layers including first and second ceramic layers (c1, c2) stacked together, the first ceramic layer being located closer to the back surface of the package body than the second ceramic layer, an interlayer surface between the first and second ceramic layers (c1, c2) being defined along an extension of a bottom surface of the recessed cavity in a plane direction; a plurality of electrode pads (8; 8A; 8B) disposed on the bottom surface of the recessed cavity and the interlayer surface between the first and second ceramic layers (c1, c2); a plurality of outer connection terminals (14; 14c) disposed on the back surface of the package body; via conductors extending through at least the first ceramic layer and respectively connecting the electrode pads (8; 8A; 8B) to the outer connection terminals, wherein each of the electrode pads (8; 8A; 8B) includes a pad body portion (8x; 8y; 8z) having a polygonal shape in plan view and an interlayer pad portion (9; 9a; 9b) formed along the interlayer surface between the first and second ceramic layers (c1, c2) such that a boundary of the pad body portion (8x; 8y; 8z) and the interlayer pad portion (9; 9a; 9b) is positioned at the interlayer surface between the first and second ceramic layers (c1, c2), wherein the interlayer pad portion (9; 9a; 9b) has a protruding part (10; 10a; 10b; 10c) protruding outwardly from the pad body portion (8x; 8y; 8z) in plan view, and wherein the via conductors are formed between the protruding parts (10; 10a; 10b; 10c) of the electrode pads (8; 8A; 8B) and the outer connection terminals through at least the first ceramic layer. a package body having opposite front and back surfaces (3, 4) and defining therein a recessed cavity open at the front surface of the package body to be filled with the liquid-containing electrolyte, the package body comprising a plurality of ceramic layers including first and second ceramic layers (c1, c2) stacked together, the first ceramic layer being located closer to the back surface of the package body than the second ceramic layer, an interlayer surface between the first and second ceramic layers (c1, c2) being defined along an extension of a bottom surface of the recessed cavity in a plane direction; a plurality of electrode pads (8; 8A; 8B) disposed on the bottom surface of the recessed cavity and the interlayer surface between the first and second ceramic layers (c1, c2); a plurality of outer connection terminals (14; 14c) disposed on the back surface of the package body; via conductors extending through at least the first ceramic layer and respectively connecting the electrode pads (8; 8A; 8B) to the outer connection terminals, wherein each of the electrode pads (8; 8A; 8B) includes a pad body portion (8x; 8y; 8z) having a polygonal shape in plan view and an interlayer pad portion (9; 9a; 9b) formed along the interlayer surface between the first and second ceramic layers (c1, c2) such that a boundary of the pad body portion (8x; 8y; 8z) and the interlayer pad portion (9; 9a; 9b) is positioned at the interlayer surface between the first and second ceramic layers (c1, c2), wherein the interlayer pad portion (9; 9a; 9b) has a protruding part (10; 10a; 10b; 10c) protruding outwardly from the pad body portion (8x; 8y; 8z) in plan view, and wherein the via conductors are formed between the protruding parts (10; 10a; 10b; 10c) of the electrode pads (8; 8A; 8B) and the outer connection terminals through at least the first ceramic layer.