To take an electronic appliance such as a display outside at the time of providing a movable plate at a part under the top plate and moving this movable plate.

Concerning a system desk, a punched part 13A is provided at a part of the top plate 13 and the movable plate 14 which is normally positioned on the same plane of the top plate 13 is arranged within this part 13A. In the case, the movable plate 14 is movably provided on the rear surface side of the top plate 13 by a pair of guiding devices arranged on the rear surface side of the top plate 13. Then an elevator is arranged at the lower position of the movable plate 14 and the display 94, etc., is mounted on its elevating table. Then the elevating table can be raised when the movable plate 14 opens the part 13A. Thereby the display 94, etc., can be taken out to the upper surface side of the top plate 13A.