To prevent wasting of a printed matter output before a print job is interrupted, and eliminate time and effort for a manual post-process, in restarting the print job in a printing system including a printer and a post-process device for applying a post-process to a sheet fed out from the printer.

When a sheet transport is stopped in a printer due to a cause of stopping therein, a post-process device holds a sheet belonging to an interrupted print job in a holding section and then stops transporting sheet in the post-process device. When all remaining sheets are removed from the printer with the cause of stopping eliminated, the printer restarts printing for print data next to print data that has been printed on a the sheet last fed out of the printer before the stop, and synchronously with the restart of the printing, the post-process device accepts remainder of sheets belonging to the interrupted job and continues the post-process of the interrupted printing job using the accepted remainder of sheets and the sheet held in the holding section.