The present invention relates to a circulation-type banknote/check deposit/withdrawal apparatus using a lateral deposit/withdrawal scheme and a method of handling banknotes and checks applied thereto, wherein banknotes and checks of various sizes can be deposited and withdrawn through a single deposit/withdrawal unit; a carrying path is configured to carry the banknotes and checks deposited through the deposit/withdrawal unit in a lateral direction; and the carrying path is provided thereon with a medium alignment unit for aligning the carrying position on the carrying path of the banknotes and checks being carried thereon, so that the banknotes and checks can be carried in a state where the banknotes and checks are aligned with a predetermined alignment position on the carrying path by the medium alignment unit, and stacked into respective corresponding cassettes.