PROBLEM TO BE SOLVED: To provide a method of manufacturing a surface temperature sensor that is less likely influenced by ambient temperature and is excellent in responsibility.SOLUTION: A manufacturing method of a surface temperature sensor includes the steps of: forming a through-hole on a bottom wall in a protective tube having a bottomed cylindrical shape; inserting a pair of thermocouple element wires forming thermocouple from the open end side of the protective tube, and inserting the tip part of the pair of thermocouple element wires into the through-hole; welding the pair of thermocouple element wires with each other and the bottom wall so as to shield the through hole in a state of inserting the pair of thermocouple element wires into the through-hole; and smoothing the outer surface of the bottom wall.