Terminals, printing apparatus, and digital copying machines are connected to one network N. A document managing portion of the printing apparatus stores document data received through the network N to a document data storing portion, and generates managing data of document data so as to be stored in a document managing table. When an error processing portion detects the occurrence of an error with reference to a table during the printing of document data, an error processing portion determines the other printing apparatus for a substitutive printing with reference to various kinds of tables, and transmits document data. A report sheet issuing portion generates a report sheet image showing a name of a substitutive printing apparatus, a current state of the apparatus having an error, measures to remove the error, etc., and a printing portion prints the report sheet image.