A temperature sensor (1) is provided with a temperature sensing element (2) arranged inside an exhaust channel of an internal combustion engine; a signal line (31), which is connected to the temperature sensing element (2) on a leading end side and connected to a lead line on a rear end side for external circuit connection; an inner member (18) having a sheath pin (3) storing the signal line (31) inside; and an outer member (13) arranged to cover at least a part of the outer circumference of the inner member (18). The outer member (13) is provided with a fixing section (rib (6)) fixed to the outer wall of the exhaust channel; a holding section (132) for holding the inner member (18); and an extending section (131) formed closer to the leading end than the holding section (132). The extending section (131) is provided with a clearance section (19) arranged at an interval from the inner member (18), and a leading end interference section (133) arranged to have a maximum interval of 0.2mm or shorter from the inner member (18) in the diameter direction.
