An image managing apparatus for managing a plurality of image data units includes: an image data acquiring unit for acquiring the image data units; an attribute information acquiring unit for acquiring attribute information units respectively associated with the image data units in such a manner that each attribute information unit corresponds to an associated one of the image data units; an image data classifying unit for classifying the image data units into a plurality of image-data groups based on the attribute information units; a thumbnail image creating unit for creating thumbnail image data units in order to display the image data units as thumbnail images; and a display unit for displaying the thumbnail images for each image-data group.