Patent ID: 8591712

Claim:
A gas sensor element for detecting the concentration of a specific gas component in gas under measurement, comprising: a plate-shaped solid electrolyte layer extending in a longitudinal direction thereof; a pair of sensor electrodes arranged on a front side of the solid electrolyte layer; a pair of sensor leads arranged on a rear side of the solid electrolyte layer and electrically connected to the respective sensor electrode; and insulating layers, one of which is arranged between one of the sensor leads and the solid electrolyte layer and the other of which is arranged between the other sensor lead and the solid electrolyte layer, wherein the sensor electrodes have rear end portions located on the insulating layers and overlapping front end portions of the sensor leads, respectively, and wherein the sensor leads are denser than the sensor electrodes and have front ends located in the same positions as or positions rear of front ends of the insulating layers, respectively.