PURPOSE: To provide an annunciator which rings at an arbitrary set cooking temperature if a heating cooker has a metal cover.

CONSTITUTION: A transmitter 3, a receiver 4, a transmitter electrode 3a and a receiver electrode 4a are formed to be exposed in an insulated state on the lower surface of a leg piece 2 for supporting a body 1, and at least the receiver 4 is formed out of a conductive material having a high thermal expansion coefficient. A switch piece 4 energized by an operation for always rotating toward a noncontact direction by a spring 6 is engaged with the part of the piece 2, and a screw type contact 7 is installed oppositely to a contact 5a. The end of an expansion operating piece 8 formed at the part of the receiver 4 is brought into contact with the piece 5, an operating circuit 9 is wired between the contact 5a and the electrode 4a, and a power source provided with a battery 11 and a ringing unit 12 is wired between the contact 7a and the electrode 3a.