Patent ID: 7811434

Claim:
A gas sensor comprising a gas detecting element extending in a longitudinal direction and in which a plurality of ceramic layers are stacked, and wherein a detecting portion is provided at a leading end side of the gas detecting element, the gas detecting element comprising: a first ceramic layer having a first surface and a second surface and having a first through hole penetrating therethrough; a second ceramic layer having a first surface and a second surface and having a second through hole penetrating therethrough; a first through-hole conductor provided on an inner peripheral surface of the first through hole; a first peripheral portion provided on the second surface of the first ceramic layer at a periphery of the first through hole and electrically connected to the first through-hole conductor; a second through-hole conductor provided on an inner peripheral surface of the second through hole; a second peripheral portion provided on the first surface of the second ceramic layer at a periphery of the second through hole and electrically connecting the second through-hole conductor and the first peripheral portion; and an opening formed by an inner peripheral surface of the first through-hole conductor and an inner peripheral surface of the second through-hole conductor, wherein the first peripheral portion and the second peripheral portion have mutually overlapping adhered portions and separated portions opposing each other through a gap continuing to the opening, and a relationship L 1 >S 1 is satisfied, where L 1 represents a maximum length of the adhered portion, and S 1 represents a maximum length of the separated portion.