GAS SENSOR

摘要

Disclosed is a gas sensor which has improved detection sensitivity and responsivity to odor gases such as ethyl acetate, while being reducing in influences from combustible gases such as hydrogen and oxidizing gases such as NOx. A gas sensor (1) has a structure wherein an insulating coating layer (3) is formed on the upper surface of a silicon substrate (2), a heating resistor (5) is arranged within the insulating coating layer (3), and an adhesion layer (7) and a gas sensing layer (4) are formed on the upper surface of the insulating coating layer (3). Namely, the gas sensor (1) has a structure wherein the gas sensing layer (4) is formed on a base which contains the silicon substrate (2) with a diaphragm structure. The gas sensing layer (4) contains Ir, P and Pt, while containing not less than 90% by mass of SnO2. The contents of Ir, P and Pt relative to the gas sensing layer (4) are so set as to satisfy the following formula: Ir = P + Pt, in terms of mass percentages of the Ir, P and Pt contents.