A brine supply unit for supplying brine to at least one load after controlling the brine so as to meet a target temperature of the load comprises: a heat exchanger disposed at a brine-cooling channel, through which the brine returned from the load flows, for cooling the brine with water for industrial use; a heater disposed at a brine-heating channel formed in parallel with the brine-cooling channel, through which the brine flows, for heating the brine; a mixing section disposed at a connecting portion between the brine-cooling channel and the brine-heating channel, for mixing the cooled brine and the heated brine; and a tank disposed between the mixing section and the load, which has a capacity of about 10 liters or more and is constructed so that the brine can pass therethrough slowly to relieve a sudden temperature change of the brine.