Abstract: The expansion device (2) provided for the attachment of a flat panel display (1) has at least one module (31, . . . , 3n), including a computer module (31), which serves to store, transmit or process video/graphics information which is transmittable to the large-format display unit (12) of the flat panel display (1), said display unit being held by a supporting structure (10). According to the invention, the expansion device (2) has a support device (21) with at least one retaining element (2110, 2120) which is located on the top of the support device (21) and is able to engage a correspondingly designed receiving part (101) located on the bottom of the supporting structure (10) of the flat panel display (1), and which retaining element is able to hold the supporting structure (10) in a fixed position relative to the support device (21).