Disclosed is a technique for bottling and commercializing—in a state provided with long-term storage stability—a carbonated beverage containing soybean powder and/or soy milk. By means of filling a bottle, of which the transmittance of light rays having a wavelength of 250-650 nm is no greater than 10%, with the carbonated beverage containing soybean powder and/or soy milk, it is possible to suppress a decrease in flavor and secure the long-term storage stability of the carbonated beverage containing soybean powder and/or soy milk.