Nowadays the banks, with a wide spread of credit transaction practice in every business, offer better services to their customers, while the automation of banking is being made more rapid progress in th light of efficient banking service. For example, it is true that the automation of cash payment for customers goes on its progress and the competition between companies is getting more serious. Lately the banks that pursue "Banking Automation System" expand distribution of cash dispenser for the better electronic computer service and for the better service for their customers in quality. Therefore the makers producing "CD" accelerate their development of CD in various ways in order to secure MIS as the leading group of th field. CD, a kind of an automatic paying, is being used generally, and has various functions and its design is getting more compact than ever. Under this situation, I studied more trustworthy and convenient CD design suggestions in the way of case study on the basis of the process of developing CD and I suggest the better way of developing the design of CD in the future.of CD in the future.