The present invention provides an ozonated water generator which can generate highly soluble and highly concentrated ozonated water in an efficient and simple manner. In an ozonated water generator comprising a supply tube for transmitting a treated liquid, a gas/liquid mixing device provided in the path of the supply tube, and an ozone supply structure for supplying ozone to the gas/liquid mixing device. The gas/liquid mixing device is provided with a magnet for creating magnetic force in the interior. Creating magnetic force in both the treated liquid and the ozone makes it possible to generate highly soluble and highly concentrated ozonated water in an efficient and simple manner.