PURPOSE: To prevent the leakage of a fluid regulating valve in a throttled condition with fine particles entrapped in a gap by providing the first and second valve bodies so interlocked for operation with respective valve seats of the first and second flow passages as to be in contact therewith or separated therefrom, and approximately balanced with each other against pressure, and further providing a resistance means in the second flow passage.

CONSTITUTION: A flow regulating valve 51 opens upon start of hot water supply, and a controller 53 regulates a flow of electric current to a solenoid 45 on the basis of a deviation between hot water temperature in a temperature setting unit 52 and a signal from a thermister 50, thereby energizing an automatic pressure regulating valve body 4 and controlling the temperature of mixed hot water in cooperation with equal differential regulating valves 47 and 48. The first hot water side valve body 31, second hot water side valve body (resistance body) 33, the first water side valve body 36 and second water side valve body (resistance body) 38, are so constituted as to be in contact with or separated from respective valve seats, and not slidable. Even if fine particles are carried in hot water or water, therefore, a small gap is free from locking due to the inclusion of the aforesaid fine particles. Also, each type of secondary pressure basically acts on a piston 41, and a fluid leakage becomes extremely small, even if the gap is set at such a size as not entrapping the fine particles.