To reduce required space for a computer when it is not used by suspending a table plate at the rear end on an immovable upper plate above in such a manner that the table plate can be freely moved back and forth and by supporting the table plate at the front end by two legs on the floor.

An upper plate 3 is provided, on the back side in both end sections, with a pair of U-shaped rails running in parallel to each other in the direction perpendicular to the longitudinal direction of the upper plate 3. A table plate 9 on which a keyboard for a computer is to be placed is shorter than a distance between leg frames 1 that support the upper plate 3, approximately as wide as the upper plate 3, and has a concave 10 at the center of the front end. The table plate 9 is provided, on the rear side in both end sections, with a pair of supporting plates 11 facing upwards, each supporting plate 11 having a roller unit on the top which is set into a rail 6 to suspend the rear end of the table plate 9 on the upper plate 3, leaving a sufficient space between the upper plate 3 and table plate 9 to allow the keyboard to pass. The table plate 9 is supported at the front end by a pair of legs 13 to keep itself horizontal, each leg 13 being provided with a caster 14 at the bottom which can run on the floor. The table plate 9 can be pushed into the space below the upper plate 3, while carrying the keyboard thereon, when the computer is not used.