PURPOSE: To provide a fire detecting system capable of detecting, in the early stages and surely, the fire of cargo compartments of aircraft, holds of vessels, warehouses or the like, and the fire occurring inside the containers accommodated therein.

CONSTITUTION: This system comprises a wireless fire detector 6 installed inside a container 4 accommodated in a cargo compartment 1 or the like, for detecting a fire if the fire occurs in the container 4 and for sending a wireless fire signal, and a fire receiver 5 installed outside the container 4 for receiving the wireless fire signal.