A method for manufacturing a thickened carbonated beverage packed in a container, said method comprising: mixing an aqueous solution of a first thickener at a temperature of 0-35°C with a second thickener, which is insoluble in water at 0-35°C but soluble in water at 60°C or higher, to give a stock liquid in which the second thickener is dispersed in the aqueous solution； dissolving carbon dioxide gas in the stock liquid to give a carbonated aqueous solution； filling the carbonated aqueous solution into a container and sealing the container to give the carbonated aqueous solution packed in the container； and then heating the carbonated aqueous solution packed in the container in such a manner that the carbonated aqueous solution attains a temperature of 60°C or higher to thereby dissolve the second thickener in the carbonated aqueous solution.
