A highly reliable automatic transaction apparatus and control method thereof which are capable of suppressing unauthorized transactions and the like are proposed. A plurality of modules which each execute processing required for the payout transaction, an overall control unit which controls each of the modules, and a security control unit are provided in an automatic transaction apparatus; the security control unit holds in advance a first list in which content of signals which are exchanged between the overall control unit and each of the modules at the time of a normal payout transaction is recorded in the order in which the signals are exchanged, sequentially records the content of the signals which are exchanged between the overall control unit and each of the modules at the time of the actual payout transaction in a second list in the order in which the signals are exchanged, and issues a signature approving operation of the modules when there is a match between the content of the first list and the content of the second list, and the modules execute a corresponding operation when the security control unit has issued the signature.