Document checking apparatus

A document checking apparatus, comprising:

• an image scanning device configured to scan a document image sheet by sheet from a document including plural sheets;
• a printing device;
• an output tray as an output destination of both the document outputted from the image scanning device and a print sheet outputted from the printing device;
• and
• a controller configured to perform checking of the document image, and if an error is detected in the checking of the document image, control the printing device and thereby insert the print sheet as an interleaving sheet immediately before or immediately after a sheet where the error is detected;
• and the controller causes the printing device to print an explanation of the error on the print sheet as the interleaving sheet.