PURPOSE: To quickly inform a transaction customer of his/her account balance by using an account number read out of the magnetic stripes of a bankbook to receive the account balance from a central computer and to display this balance on a display device.

CONSTITUTION: A customer puts his/her card into an automatic cash transaction device 10 and inputs a personal identification number via an operation button. Thus the balance of the transaction account received from a central computer 20 is shown on an operation guide screen of a display device. In this case, the device 10 uses the account number read out of the magnetic stripes as a key to send a message to the computer 20 and receives the unregistered data and the answer of the balance amount from the computer 20. The balance amount and the unregistered data are once stored in an arithmetic control mechanism 15, and the unregistered data is printed on a bankbook. Thus it is possible to obtain such an automatic cash transaction device that can inform the customer at the high speed of his/her account balance and contribute to the input of the amounts to be received and paid respectively.