To provide a top plate of desk or the like convenient not only for a business processing by a notebook-sized personal computer but also for a normal business processing or the like by securing a wide top surface in the case of housing the notebook-sized personal computer.

This top plate 2 is in a hollow double wall structure constituted of a top surface wall 4 and a back surface wall 6 at a fixed interval and a peripheral end wall 6 for integrally closing the periphery. The top plate 2 is equipped with a power introducing connector 13 and a socket 14 electrically connected to the power introducing connector 13 through the hollow part of the top plate 2. On the top surface wall 4 of the top plate 2, a recessed part 10 for flatly housing the notebook-sized personal computer is provided. A lid body 11 for covering the recessed part 10 so as to form the same surface as the top surface is provided.