To provide an excellent temperature reducer which can efficiently mix sprayed water with a high-temperature drain and has a simple structure and a high degree of freedom for installation location.

This temperature reducer is provided with a plurality of water spray nozzles having ejectros in a drain pipe into which the high-temperature drain is discharged from a blow tank and lowers the temperature of the drain by spraying water from the ejectors upon the drain flowing through the drain pipe, the water spray nozzles are composed of circular pipes each having a sealed front end and many ejectors bored at intervals in the axial direction of the pipe and are installed in such a way that the nozzles are fixed after the nozzles are passed through the drain pipe.