Temperature sensor

A temperature sensor comprising:

• a temperature sensitive element having an electrical property that changes with temperature;
• a sheath member including at least one conductor extending in a lengthwise direction of the temperature sensor and is electrically connected to the temperature sensitive element directly or through another member, an insulator formed of an insulating material and surrounding the at least one conductor, a metallic cladding member covering the insulator and open at opposite ends in the lengthwise direction, and seal members sealing the open opposite ends of the metallic cladding member with the at least one conductor extending outward from the metallic cladding member through the seal members;
• and
• a covering member formed mainly of glass and covering a junction between the at least one conductor and the temperature sensitive element or a junction between the another member and the temperature sensitive element,
• wherein:
• an electric resistance of the temperature sensitive element increases with the temperature, and
• an insulation resistance of the seal members is equal to or greater than an insulation resistance of the covering member.