To optimize the emission of extinguishing agent liquid from the head based on the combination of water flow detection by head operation and fire detection by a fire detecting device.

Extinguishing agent supplied from the agent tank 22 is mixed into the water for fire-fighting supplied under pressure from the fire extinguishing pump 10 by the mixer at the time of fire, and the extinguishing agent liquid is supplied to the open operated closed head 34 connected to the branch pipe 26 to be emitted. The controller 48 maintains the control valve at the streaming detection device 28 and the main valve 24 at the agent tank opened during normal times. If the fire signal E2 is obtained when the streaming detection signal E1 is obtained, the control valve and the main valve 24 at the agent tank 24 are maintained to be opened. If the fire signal E2 is not obtained when the streaming detection signal E1 is obtained, the control valve at the streaming detection device 28 and the main valve 24 at the agent tank are controlled to be closed and afterwards, when the fire signal E2 is obtained, the control valve of the streaming detection device 28 and the main valve 24 of the agent tank is controlled to be opened.