PURPOSE: To provide a system capable of applying the batch processing of format conversion, data processing or its succeeding processing especially to plural files only by specifying contents to be processed.

CONSTITUTION: Formats before and after conversion, the contents of data processing, the contents of post processing, or the like are specified by client computers CC (1 to n). Files or data to be processed are transferred from the client computers CC (1 to n) to a server computer SC together with these conditions. The format conversion or data processing of the transferred file or the like is executed by the server computer SC. Then specified post processing, e.g. printing-out, is executed. When plural files or data are especially specified so as to be processed, the processing of these files or data is collectively executed by the server computer SC.