An apparatus for producing carbonated water, the apparatus comprising: a water tank in which water for producing the carbonated water is stored; a water supply passage connected to a cold water storage unit to supply the water; a gas cylinder in which a carbon dioxide gas is filled; a gas supply passage connected to the gas cylinder to supply a carbon dioxide gas; a mixing unit connected to the water supply passage and the gas supply passage and in which the carbon dioxide gas is introduced by a low pressure generated by flow velocity of supplied water to mix the water with carbon dioxide; a gas regulator disposed in the gas supply passage for supplying the carbon dioxide gas at a predetermined pressure into the mixing unit; and a dispensing passage connected to the mixing unit to discharge the produced carbonated water; characterized in that the apparatus further comprises: a pressing passage branched from the gas supply passage and connected to the water supply passage, and a pressing regulator disposed in the pressing passage for supplying the carbon dioxide gas into the water supply passage so that the water flowing along the water supply passage may flow at a predetermined pressure, wherein the pressing regulator is set to a pressure greater than that of the gas regulator so that the water supplied into the mixing unit is supplied at a predetermined pressure. a water tank in which water for producing the carbonated water is stored; a water supply passage connected to a cold water storage unit to supply the water; a gas cylinder in which a carbon dioxide gas is filled; a gas supply passage connected to the gas cylinder to supply a carbon dioxide gas; a mixing unit connected to the water supply passage and the gas supply passage and in which the carbon dioxide gas is introduced by a low pressure generated by flow velocity of supplied water to mix the water with carbon dioxide; a gas regulator disposed in the gas supply passage for supplying the carbon dioxide gas at a predetermined pressure into the mixing unit; and a dispensing passage connected to the mixing unit to discharge the produced carbonated water; characterized in that the apparatus further comprises: a pressing passage branched from the gas supply passage and connected to the water supply passage, and a pressing regulator disposed in the pressing passage for supplying the carbon dioxide gas into the water supply passage so that the water flowing along the water supply passage may flow at a predetermined pressure, wherein the pressing regulator is set to a pressure greater than that of the gas regulator so that the water supplied into the mixing unit is supplied at a predetermined pressure. a pressing passage branched from the gas supply passage and connected to the water supply passage, and a pressing regulator disposed in the pressing passage for supplying the carbon dioxide gas into the water supply passage so that the water flowing along the water supply passage may flow at a predetermined pressure, wherein the pressing regulator is set to a pressure greater than that of the gas regulator so that the water supplied into the mixing unit is supplied at a predetermined pressure.