To facilitate retransmission of a data file that has been deleted from a server, a data processing device includes a first storage section in which a management table is stored. The management table includes a list of communication histories with respect to communications with each of the servers. Each communication history indicates a data file transmitted to the server. The device further includes a second storage section storing data files transmitted to the servers. A control section is provided for judging, when a communication section is in communication with a server, whether or not a data file which has already been transmitted to the server needs to be retransmitted and retransmit the data file to the server upon retrieving the data file from the second storage section when judgment is made so that retransmission of the data file is needed.