To provide a small and lightweight temperature-sensitive circuit breaking component irreversibly operated with an electrical mechanism and operable at high sensitivity at a temperature at the same level as room temperature; and to provide a current-carrying circuit using it.

This temperature-sensitive circuit breaking component includes: a case body 1 equipped with an opening 2 having, in its inside, an acidic constituent, paraffin containing a substance generating a gas by reacting with the acidic constituent and water, and having an opening 2; a first conductor 3 mounted on a surface of the case body 1; and a second conductor 4 mounted on the opening 2 so as to be electrically connected to the first conductor 3. The temperature-sensitive circuit breaking component is so structured that the acidic constituent is reacted with the substance generating a gas by reacting with the acidic constituent in the presence of water to generate the gas with fusion of the paraffin at a predetermined temperature; the internal pressure of the case body 1 is increased by the gas, whereby the content in the case body 1 is spouted from the opening 2; and the second conductor 4 on the opening 2 is separated from the first conductor 3 by the spouting force, whereby the circuit is broken.