Gas sensor

A gas sensor comprising:

• a plate-shaped gas sensing element extending in a longitudinal direction and comprising a sensing portion provided at a leading-end side in the longitudinal direction, the gas sensing element comprising a plurality of stacked ceramic layers including a first ceramic layer having a first surface and a second ceramic layer having a second surface opposing the first surface,
• wherein the first ceramic layer has a first through hole, a first through hole conductor covering at least an inner surface of the first through hole,
• wherein the first ceramic layer comprises a first conductor formed on the first surface thereof,
• wherein the first conductor comprises:
• a first peripheral conductive portion provided at a periphery of the first through hole and electrically connected to the first through hole conductor;
• a first lead portion that is narrower than the first peripheral conductive portion;
• and a first contact conductive portion that is wider than the first lead portion,
• wherein the first peripheral conductive portion, the first lead portion and the first contact conductive portion are integrally formed and arranged in this order in the longitudinal direction, and
• wherein the second ceramic layer comprises a second conductor formed on the second surface thereof and electrically connected to at least the first contact conductive portion.