A paper money processor according to the present invention includes a transaction slot where paper money is at least either inserted or dispensed with an orientation such that one of lengthwise ends of the paper money is positioned at a side of a first lengthwise end of the transaction slot. The transaction slot includes a main opening which opens on a second lengthwise end of the transaction slot, and a lateral opening which is continuous with the main opening, and opens on a first widthwise end of the transaction slot.