PURPOSE: To provide a warm/ chilled water manufacturing apparatus in which wastes of water resource and energy are small and warm water and chilled water can be efficiently manufactured even if utilization rates of the warm water and the chilled water such as using amounts of the warm and chilled waters and consumption heat quantity of load are different.

CONSTITUTION: A water supply part such as a water feed tube 50, etc., is provided on the way of a circulation passage from a warm water tank 30 of a warm water circulation passage 32 to a warm heat generator 14, a drain part such as a drain tube 70, etc., is provided on the way of a circulation passage from the generator 14 to the tank 30 is provided, a water supply part such as a water feed tube 40, etc., is provided on the way of a circulation passage from a chilled water tank 20 to a cold generator 12, and a drain part such as a drain tube 50, etc., is provided on the way of a circulation passage from the generator 12 to the tank 20.