An electronic money system terminates communication to a management center indistinguishably from a case in which the communication to the management center is completed within a predetermined period when it is impossible to complete the communication to the management center within the predetermined period. By switching an operation mode, a predetermined portable terminal is used instead of a communication line to upload and download data. When it is impossible to obtain data required for processing through the communication line, processing is performed based on data possessed up until that time.