Provided is a display device including a display mode controller for controlling a transition to a whole screen display mode for displaying an image in an entire screen of a display section, a multiple content display mode for displaying, on the screen, multiple thumbnail images related to contents, or a panel display mode for displaying, on the screen, a panel on which information related to the contents is displayed, an arrangement determination section for arranging multiple thumbnail images displayed in the multiple content display mode by category to which the contents belong, an arrangement change section for changing an arrangement of multiple thumbnail images by a user, and a boundary line display section for displaying, between two thumbnail images, a boundary line indicating a difference of the category before the arrangement of the thumbnail images is changed by the user, and for not displaying the boundary line after changed.