1. A playback device comprising: a command input unit to accept a manipulation command entered by a user; a display controller to generate image data on a manipulating-function menu screen including a plurality of identification miniature images for respective ones of a plurality of to-be-replayed objects; and a display output unit to output the manipulating-function menu screen image data from the display controller to a display unit, the display controller functioning to: display the plurality of identification miniature images for respective ones of the plurality of to-be-replayed objects simultaneously on one display screen with taking one of the to-be-replayed objects corresponding to one of the identification miniature images in a predetermined position as a to-be-replayed object of interest, while displaying a first group of a plurality of manipulating-function items for each of the to-be-replayed objects and a second group of a plurality of manipulating-function items for each of the plurality of to-be-replayed objects so that one of the manipulating-function items can be selected by an operation made via the command input unit, with an indication of which one of the manipulating-function items is being selected; and display, during selection of any one of the manipulating-function items included in the first group, the identification miniature image corresponding to the to-be-replayed object of interest in such a manner that the identification miniature image can be differentiated from the other identification miniature images, wherein a plurality of types of media can be replayed, a plurality of contents in each of the media can be replayed, and the to-be-replayed object is the content that can be replayed; the identification miniature images corresponding to the to-be-replayed objects are taken as first identification miniature images while the identification miniature images corresponding to the respective ones of the plurality of types of media are taken as second identification miniature images; the display controller functions to: display a menu in which the plurality of first identification miniature images is arrayed in a first display area extending in a first direction on the display screen and the plurality of second identification miniature images is arrayed in a second display area extending in a second direction, the first and second display areas intersecting near a center of the display screen, and a content corresponding to one of the first identification miniature images positioned near the intersection is taken as a content in the to-be-replayed object of interest; and display, in the display screen displaying the menu having displayed thereon the intersecting first and second display areas, when a predetermined operation is made by the command input unit, the manipulating-function menu screen (a) moves the first display area with the plurality of first identification miniature images therein from the center of the display screen to one side of the display screen, (b) deletes the second display area with the plurality of second identification miniature images therein from the display screen, (c) displays a third display area which displays the first group of a plurality of manipulation-function items for individually manipulating each to-be-displayed objects, and (d) displays a fourth display area which displays the second group of a plurality of manipulation-function items for manipulating the entire plurality of to-be-replayed objects.