A temperature sensor includes a thermo-sensitive element, a pair of element electrode wires electrically connected to the thermo-sensitive element, a glass sealing body that covers the thermo-sensitive element and part of the pair of the element electrode wires, and a tablet formed with a pair of insertion holes extending in an axial direction thereof, through which the pair of the element electrode wires pass respectively. The glass sealing body includes a sealing part formed so as to extend from an element side end surface thereof located on a side of the thermo-sensitive element toward the thermo-sensitive element, and a sagging part formed in each of the pair of the insertion holes so as to extend integrally from the sealing part. The length of the sagging part in the axial direction being smaller than or equal to 1.5 mm.