Produce high-function water useful for consumption as healthy drinking water or in the production of health supplements, cosmetic products, food preservatives, freshness-keeping agents for food, insect repellents or deodorizers, wherein such water contains micro-dispersed ultra-fine gold particles and a small amount of dissolved gold and is produced by constructing in the upper section of a high-pressure water tank a combustion chamber equipped with an injector nozzle for oxygen-hydrogen mixture gas, an ignition device and a gold-rod or gold-wire feeder, igniting the injector nozzle for oxygen-hydrogen mixture gas using the ignition device in the combustion chamber to melt and evaporate the gold rod or wire supplied from the feeder or water in which gold foil was dispersed beforehand and to allow the produced gold vapor to contact high-pressure water, and thereby causing the produced ultra-fine gold particles to float and disperse in water.