To provide a fire sensor for improving the detecting accuracy of a fire and a fire extinguishing device for improving fire extinguishing efficiency.

The fire sensor 50 installed at a monitor object for monitoring the fire of the monitor object is provided with a sensing part 53 for detecting the fire of the monitor object; and a communication part 56 for, when the fire of the monitor object is detected by the sensing part 53, transmitting notification information for notifying a user the fact that the fire has been detected. Especially, the fire sensor 50 is provided with an electromotive force part 52 for converting the heat of the monitor object into a power, and a communication part 56 transmits notification information, by using a power generated by the electromotive force part 52. Also, the fire sensor is provided with an identification table 55a for recording an ID number for uniquely identifying the fire sensor, and the communication means transmits the ID number stored in the identification table 55a as the notification information.