Method and apparatus for electronic memo processing for integrally managing document including paper document and electronic memo added to the document

An electronic memo adding and displaying apparatus 50 includes a tablet with integrated display for electronically acquiring an electronic memo to a document input by a user through a virtual transparent input sheet registered to be overlapped with an arbitrary object document 52, and for displaying the electronic memo on the virtual transparent input sheet, and a control unit 58 performing an electronic memo storing process, for storing the electronic memo acquired through the tablet with integrated display in a storage while associating the electronic memo with the object document.