A method of manufacturing a high quality beverage capable of providing beverage by an extraction after roasting the material thereof and filling beverage of a roast material in a container and sealing the container. The method comprises a step for roasting the material in a sterile atmosphere, and extracting the roast material or preparing a suspension of the roast material with sterilized water, wherein sterilized inert gas atmosphere is used as the sterile atmosphere in at least a part of the step, whereby since both the deterioration of quality due to oxidation and the deterioration of quality by heating can be prevented, the high quality beverage of the roast material can be manufactured.