To provide a carbonated water producing device capable of efficiently producing a carbonated water having a high dissolution rate of carbon dioxide, namely, having a high gas volume at low cost.

In a pressure container 41, there are provided a carbon dioxide nozzle 42 for introducing a carbon dioxide 46 from the outside, a water injection nozzle 50 for injecting a drinking water 47 as a swirl flow at a predetermined injection angle from an upper part center into a pressurized carbon dioxide atmosphere in the pressure container 41, a carbonated water supply pipe 44 for causing a carbonated water 48 accumulated in the pressure container 41 to flow outside, and a patch plate 45 having a slope 45a descending from the center to the periphery in the carbonated water 48, the patch plate disposed facing and below the water injection nozzle 50. The drinking water 47 of the swirl flow at the predetermined injection angle is injected in the atmosphere of the carbon dioxide 46, which is supplied in the pressure container 41 from the carbon dioxide nozzle 42, from the water injection nozzle 50, and the carbonated water 48 is produced.