Patent ID: 7819996

Claim:
A method of manufacturing a gas sensing element for detecting a specified gas concentration in measuring gases, comprising the steps of: preparing first to third unfired green sheets for a sensing layer, a reference gas airspace forming layer and a heating layer, respectively; pressuring the first to third unfired green sheets with a pressure of 10 MPa at a temperature above 60° C. such that each of the first to third unfired green sheets has porosity greater than 5% and less than 7.5%; printing an electrically conductive paste on surfaces of the first unfired green sheet; preparing the sensing layer by forming a measuring gas side electrode on one surface of the first unfired green sheet and forming a reference gas side electrode on the other surface of the first unfired green sheet; preparing the reference gas airspace forming layer using the second unfired green sheet; preparing the heating layer by forming a heating section on the third unfired green sheet at one surface thereof in face with the sensing layer; stacking a shielding layer, a porous diffusion resistance layer, the sensing layer, the reference gas airspace forming layer and the heating layer to form a stacked ceramic body; and firing the stacked ceramic body for thereby obtaining the gas sensing element.