The present invention provides a financial automated-teller machine comprising a main body having an operation unit and a cash deposit/withdrawal unit installed at a front face thereof; a safety door having a locking function and hingedly connected to an edge of the front face of the main body; a safe that is disposed within the main body and is opened and closed by means of the safety door; a bill storage unit with a bill-receiving and dispensing function for allowing a deposited bill to be received therein and a bill to be withdrawn to be dispensed therefrom; and a base that has the bill storage unit mounted thereon, is placed within the safe when the safety door is closed, can be withdrawn to the outside of the safe when the safety door is opened, and is provided with a first guide at a lower portion thereof so that the base can be withdrawn along the first guide. Thus, a maintenance work, particularly, a replacement work for the bill storage unit can be easily performed in an inner working space of a kiosk which is narrow in a fore and aft direction, and the maintenance work does not cause inconvenience to travelling cars or walkers. The present invention further provides a method of withdrawing a cassette provided in the automated-teller machine.