This temperature sensor is provided with a temperature detection unit (2), an element electrode wire (23), a lead wire (3), and an intermediate member (4). The lead wire (3) and the intermediate member (4) are made of an Ni-base alloy or an Fe-base alloy. The element electrode wire (23) and the intermediate member (4) are welded to each other, with opposing surfaces (231 and 41) thereof butted against each other, to form an element-side welded part (51). The intermediate member (4) and the lead wire (3) are placed one upon the other in the vertical direction Z and welded to each other to form a lead-side welded part (52). The lead wire (3) extends to the temperature detection unit (2) side of the element-side welded part (51). A filler (62) is filled at least in a gap between the element electrode wire (23) and the lead wire (3) in the vertical direction Z. The element electrode wire (23), the element-side welded part (51), and the lead wire (3) are fixed to one another by the filler (62).