Disclosed herein is an apparatus for processing a medium, including: a accepting unit in which the medium is loaded; a dispending unit from which the medium is withdrawn; a medium discriminator configured to discriminate a denomination of the medium loaded into the accepting unit; a plurality of medium storage boxes configured to each discriminate and store the medium by denomination of the medium discriminated by the medium discriminator; and a controller configured to store the medium loaded through the accepting unit by the same denomination in the medium storage box and withdraw the loaded medium from the medium storage box according to a predetermined withdrawal criterion.