An apparatus for manufacturing carbonated water according to the invention can quickly produce carbonated water with a high carbonic acid gas content which does not easily lose carbonic acid gas and hence satisfactorily stimulates the throat with agreeable pungency. Since it has a simple configuration and hence is economic and effective, it can suitably be used in a carbonated beverage supplying apparatus such as an automatic vending machine, an automatic dispenser or the like. With such an arrangement, the apparatus improves its safety and hence can constantly supply delicious carbonated water.