Patent ID: 8012324

Claim:
A sensor element comprising: a first solid electrolyte layer having a first through hole which penetrates from a first obverse surface to a first reverse surface located on a side opposite the first obverse surface; and a second solid electrolyte layer having a second through hole which penetrates from a second obverse surface to a second reverse surface located on a side opposite the second obverse surface and which overlaps the first through hole in a penetrating direction, the second solid electrolyte layer being stacked on the first solid electrolyte layer by bringing the first reverse surface and the second obverse surface into contact with one another directly or through another member, the first solid electrolyte layer comprising a first inner insulating layer provided on an inner surface of the first through hole, a first outer insulating layer connected to the first inner insulating layer and provided on the first reverse surface, a first inner conductive layer provided on the first inner insulating layer, and a first outer conductive layer directly connected to the first inner conductive layer and provided on the first outer insulating layer, the second solid electrolyte layer comprising a second inner insulating layer provided on an inner surface of the second through hole, a second outer insulating layer connected to the second inner insulating layer and provided on the second obverse surface, a second inner conductive layer provided on the second inner insulating layer, and a second outer conductive layer directly connected to the second inner conductive layer and provided on the second outer insulating layer, and wherein the first outer conductive layer and the second outer conductive layer are in direct contact with one another and overlap one another in the penetrating direction.