PURPOSE: To facilitate a layout change without deteriorating the appearance by providing wiring accessories in an attaching unit attached to a top plate of a desk.

CONSTITUTION: Wiring accessories 3 are provided in an attaching unit 2 attached to a top plate 1 of a desk. The length of the attaching unit 2 is set to a length corresponding to the width of one side of the top plate 1. A recessed holding part 4 is engaged with the side peripheral portion of the top plate 1 and is fixed to the top plate 1 by clamping with clamp screws 5. The wiring accessories 3 comprise, for example, a plug socket 6 and a telephone line connecting socket 7 and are provided on the side face on the top plate side of a box member 8 provided on the attaching unit 2. The front face of the box member 8 faces the surface of the top plate 1. By attaching the attaching unit 2, the power distribution unit can flexibly correspond to a layout change. Since wiring can be housed and arranged in the unit, the clear appearance of an office can be kept.