A data generating apparatus being provided with: an extracting unit that extracts text image which is a part of the text of a file stored in a storage medium and picture image which is a part of the picture of the same; a setting unit that, for each file, sets a text thumbnail arranging region to which the text image is outputted and a picture thumbnail arranging region to which the picture image is outputted in accordance with file specifying information for specifying each file; and an index data generating unit that arranges the text image and the picture image in the set text thumbnail arranging region and the picture thumbnail arranging region, respectively, as thumbnails together with the file specifying information. Therefore, generated index data can be displayed on a display unit and can be printed by a printing unit.