Hydrocarbon sensor

The present invention relates to a hydrocarbon sensor. The invention presents a hydrocarbon sensor excellent in yield and high in detection precision. To achieve the object, the invention includes a solid electrolyte layer () contained barium-cerium oxide, a pair of electrodes, cathode () and anode (), provided on the solid electrolyte layer (), a ceramic substrate () having a coefficient of thermal expansion nearly same as that of the solid electrolyte layer (), and a heater () provided on the ceramic substrate (), in which the solid electrolyte layer () and ceramic substrate () are bonded to each other.