A temperature sensor includes: a sensor element including a heat-sensitive body configured to contact with a detection object, a pair of lead wires connected with the heat-sensitive body, and connecting wires connected with the lead wires respectively; and a holding element including a fixed body configured such that a position of the fixed body is fixed to an object appliance, and a movable body configured to support the heat-sensitive body of the sensor element and to reciprocate between a first position and a second position relative to the fixed body. Each of the lead wires includes a first core wire formed of a solid wire. Each of the connecting wires includes a second core wire formed of a twisted wire and a second insulating covering that covers the second core wire. A conducting wire constituting the twisted wire has a smaller wire diameter than the solid wire.