Temperature sensor

A temperature sensor comprising:

• a temperature sensing element for detecting a temperature;
• a pair of element electrode wires connected to the temperature sensing element, and
• a pair of terminals connected to respective ones of a pair of the element electrode wires, wherein
• the element electrode wires each have an overlapping wire portion connected to the terminal in such a manner as to overlap the terminal in an overlapping direction orthogonal to a sensor axis direction,
• a fillet portion is disposed on a side surface of the overlapping wire portion, the fillet portion having a pair of fillet pieces formed in such a manner as to crawl up from a specific main surface that is a main surface at the overlapping wire portion side in the terminal, and
• when a direction orthogonal to both the sensor axis direction and the overlapping direction is defined as a width direction, and in a cross section orthogonal to the sensor axis direction and passing through the fillet portion, a maximum length in the width direction of the fillet portion is defined as a fillet maximum width A, and a length in the width direction between a pair of boundary portions between a pair of the fillet pieces and the specific main surface is defined as a boundary width B,
• the temperature sensor has, at least partly in the sensor axis direction, a specific cross section satisfying B≤A, as a cross section orthogonal to the sensor axis direction and passing through the fillet portion.