PURPOSE: To provide a temperature sensor having a flat contact face to a body whose temperature is measured by controlling the leak amount of heat received from the body whose temperature is measured.

CONSTITUTION: A holder 31 with a through-hole 29 is overlapped on a movable side back plate 25. A metal heat receiving plate 39 is fixed on one face of the holder 31 in a manner of blocking the through-hole 29. The end of a thermocouple line 51 is fixed on the inner side of the heat receiving plate 39, and the thermocouple line 51 is guided to the outside through the throughhole 29 and an insertion hole 27 of the movable side back plate 25. The holder 31 is composed of an inorganic material having heat conductivity smaller than that of the heat receiving plate 39 to a large extent, and the holder encircles the periphery of the heat receiving plate 39 and is brought into contact with molten resin 41 together with the heat receiving plate 39 on a flat surface.