To provide a thermally-actuated switch not affected by the fluctuation of supplied current, which has an airtight container.

A thermally actuated switch 1 is constituted in an airtight container with a container 3 and a cover plate 3. A lead terminal pin 5 having a fixed contact part 6 is airtightly insulated and fixed to a disc 3A of the cover plate 3. A stationary member 7 is fixed to the disc 3A on the inside of the airtight container, and the one end of a moving plate 8 is fixed to the stationary member 7. A through hole is formed on the free end side of the moving plate 8 and a moving contact 9 is inserted into the through hole and fixed there. The moving contact 9 is also inserted into a through hole formed in the narrowed down center of a thermally actuated plate 10, and the moving plate 8 is linked to the movement of the thermally actuated plate 10. Since current does not actually flow in the thermally actuated plate 10, even when the switch is fixed to appliances in which flowing current is fluctuated, a circuit is shut off at the specified temperature without being affected by the current fluctuation.