A sensor is disclosed. The sensor includes a substrate including a cold junction area and a hot junction area and a thermocouple including a pair of thermoelectric elements which is formed to extend linearly between the cold junction area and the hot junction area, and stacked on an upper surface of the substrate. Wherein, a stepwise portion is formed adjacent to an end portion of the thermocouple by removing a portion adjacent to an end portion of one of the pair of thermoelectric elements, and a wiring part of metal is formed in the stepwise portion so as to connect electrically the pair of thermoelectric elements each other.