In a paper sheet handling apparatus, communication part or parts (29) are arranged in a bottom part of an upper assembly (12) and communication part or parts (42) are arranged in an upper part of a lower assembly (14) for exchanging banknotes between the upper assembly (12) and the lower assembly (14). The number of the communication part or parts (29) of the upper assembly (12) and the number of the communication part or parts (42) of the lower assembly (14) are same. The position or positions of the communication part or parts (29) of the upper assembly (12) and the position or positions of the communication part or parts (42) of the lower assembly (14) match when the upper assembly (12) or the lower assembly (14) is reversed.