PURPOSE: To sprinkle water to a tunnel, for which a fire generation confirming signal is outputted, when the water is not sprinkled in any tunnel by providing a second water discharge control means to send the clear signal of under-water discharge information from a second storing means in an automatic master water discharge controller when a fire extinguishment confirming signal is received.

CONSTITUTION: A water discharge demanding signal is sent from an automatic slave water discharge controller 15. Then, when the water is not sprinkled to any tunnels Tu1, Tu2...TuN, a water discharge permitting signal is sent from an automatic master water discharge controller 10 to the automatic slave water discharge controller 15 which sends the water discharge demanding signal. Then, only when there is not tunnel, to which the water is already sprinkled, the water can be sprinkled. Thus, the water is not simultaneously sprinkled from a water tank to two water discharge blocks and the information of the automatic slave water discharge controller 15 are collected to the automatic master water discharge controller 10. Then, a control state by each automatic water discharge controller is totally controlled by the automatic master water discharge controller.