A scan job for scanning in an evidenced document is transmitted from a client terminal to a scanner. The scanner executes the scan job that has been received. If the scan job to be executed designates overlay printing, form data to be overlaid with the data scanned in by the scan job is selected (S205) and the selected form and scanned-in data are overlaid (S205). As a result, user operation is simplified while wasting of paper is eliminated.