Patent ID: 7006926

Claim:
A carbon dioxide sensor provided with a detection electrode and a counter electrode on an electrolyte, wherein the detection electrode comprises a metal oxide layer including a metal oxide, and a metal carbonate layer including a metal carbonate and placed between the metal oxide layer and the electrolyte, wherein the metal oxide includes at least one element selected from the group consisting of tin oxide, indium oxide, cobalt oxide, tungsten oxide, zinc oxide, lead oxide, copper oxide, iron oxide, nickel oxide, chromium oxide, cadmium oxide and bismuth oxide, and wherein the metal carbonate includes a first component of alkali metal carbonate and a second component of at least one element selected from the group consisting of alkali earth metal carbonate, carbonate of an element selected from Group 4 to Group 11 in long-form periodic table, zinc carbonate, cadmium carbonate, indium carbonate, lead carbonate and bismuth carbonate.