GAS SENSOR ELEMENT, AND GAS SENSOR

摘要

Provided is a gas sensor element and a gas sensor, wherein the gas sensor element is covered by two porous protective layers to suppress cracks caused by water contacting the gas sensor element, and the occurrence of cracks in the inner porous layer having high porosity is suppressed for improved layer strength. A gas sensor element (100) is provided with: a detection part (150) having a solid electrolyte (105) and a pair of electrodes (104, 106) arranged on the solid electrolyte; and a porous protective layer (20) formed covering the detection part. The porous protective layer is provided with an inner porous layer (21) and an outer porous layer (23). The porosity of the inner porous layer is higher than the porosity of the outer porous layer. The inner porous layer has, as essential components thereof, ceramic particles (21a), and ceramic fibers (21b) which have ceramic as the main component thereof and which have an average fiber length of 70 to 200μm. If the total amount of ceramic particles and ceramic fibers is 100 vol%, the amount of ceramic fibers is 25 to 75 vol%.