PURPOSE: To optionally set an operating temperature, by using a thermosensitive element consisting of a thermosensitive thyristor and a combined element.

CONSTITUTION: A plurality of thermosensitive elements 2' are coupled in parallel with one another between two parallel conductors 1a', 1b'. Each thermosensitive element 2' consists of a thermosensitive thyristor having an anode A, a cathode K and a gate G and a combined element 5. A resistor, a diode or a thermistor can be used as the combined element 5. Thereby, a thermosensitive element wire is formed. The temperatures of cables of different kinds or different allowable temperature levels can be supervised by using such a thermosensitive electric wire of unit length.