To provide a sprinkler system connected to water supply, which is connected with waterworks having low watering capacity and can supply water to piping, in which a sprinkler head is installed, from the separate source of water in case of fire.

For a piping 2 for fire extinguishing, a water supply port 5 connected with an external watering device is formed or a water reservoir 10, in which water is always stored, is installed, and water is fed to the piping 2 for fire extinguishing from the water reservoir 10 in case of fire.