HYDROGEN GAS SENSOR, AND MANUFACTURING METHOD OF THE SAME

PROBLEM TO BE SOLVED: To provide a hydrogen gas sensor which has a simple structure, excellent durability, high detection sensitivity, good response time, and excellent hydrogen gas selectivity.SOLUTION: The hydrogen gas sensor includes a sensor element with titanium oxide having fine pores of inner diameters of 500 nm or less or fine cylinders of outer diameters of 1000 nm or less and formed on an insulating substrate as a main component, and the electric resistance of the sensor element varies depending on concentration of hydrogen. The sensor element is suitably an anodic oxidation film of a titanium alloy containing palladium or platinum of 0.01 mass% or more. The hydrogen gas sensor is manufactured by producing a titanium thin film or a titanium alloy thin film on the insulating substrate, and then applying anodic oxidation to the titanium thin film or the titanium alloy thin film.