Patent ID: 8257564

Claim:
A gas sensor comprising: a gas detecting element extending in an axial direction and including a detecting electrode provided on an outer surface of a leading end side of said gas detecting element, and a lead portion connecting to said detecting electrode and extending toward a rear end side of said gas detecting element; a cylindrical metal shell housing said gas detecting element such that said gas detecting element protrudes from a leading end side of said metal shell; a powder layer filling a gap between said gas detecting element and said metal shell and covering at least a portion of said lead portion; and an insulating layer provided so as to prevent direct contact between said powder layer and the gas detecting element, wherein said gas detecting element includes a porous protecting layer formed on the gas detecting element so as to cover at least a portion of said detecting electrode and overlapping at least a leading end portion of said insulating layer, wherein the insulating layer comprises glass, and wherein the insulating layer is not present at a distal end of the gas detecting element.