To effectively detect a temperature over a wide range of a plane heating element by a simple structure using a PTC element, and provide excellent durability, workability, and installation workability, and reduce cost.

This temperature sensor 1 includes a plurality of temperature detection chips 11 of a flat shape which use the PTC elements and are surrounded by a pressure-proof member 12. The sensor is serially connected by a temperature detection signal cable 13 (a silver pattern 131), and is laminated by an insulating film 14, and is formed in a ribbon shape entirely.