There is provided a novel microorganism capable of fermentation without placing particular limitations on fermentation conditions, as well as a method of processing green coffee beans using the novel microorganism, the method adding new, high-quality flavor and aroma to a coffee beverage by a simple operation, without instigating a particular increase in raw material costs and without requiring a new processing step. The method for processing green coffee beans includes a fermentation step of bringing nutritive substances and microorganisms into contact with one another and causing fermentation in the presence of green coffee beans, wherein the microorganism used in the fermentation step is a microorganism belonging to the genus Geotrichum.
