This invention provides a automatic transaction system which can complicated to register a procedure of biological information of a customer, and it is impossible to immediately perform biological authentication by the registered customer biological information and the acquired biological information of the customer after registration completion. This automatic transaction system has an automatictransaction device having: a biological information acquisition part acquiring the biological information from the customer; and a biological authentication part comparing the acquired biological information and the registration customer biological information received from a portable terminal of the customer, and performing the biological authentication. The automatic transaction system also has: an instruction part instructing the acquisition of the biological information of the customer to be registered in advance as the registration customer biological information; and a communication control part transmitting the acquired biological information of the customer to the portable terminal when performing identification of the customer. The portable terminal has: a data registration part registering the biological information into a storage part as the registration customer biological information when receiving the biological information; and a communication part transmitting the registration customer biological information to the automatic transaction device when receiving a transmission instruction from the automatic transaction device in transaction processing.