PROBLEM TO BE SOLVED: To provide a money exchanger capable of maintaining fairness between it and a counter in a banking institution concerning a commission of a money exchange transaction.SOLUTION: When denomination of bills to be deposited overlap with denominations of bills to be dispensed in a money exchange transaction, the money exchanger subtracts the number of bills of overlapped denominations from the number of bills of the same denominations to be dispensed so as to obtain the number of bills as a charging target number. Thus, a commission rule in money exchange transaction by the money exchanger can be brought close to a money exchange rule in a counter in a banking institution. As a result, users of the banking institution are promoted to use the money exchanger.