To compact a mechanism for vertically moving a storage box.

The storage box 3 composed of an upper plate part 3a for closing an opening part 2 opened on the top plate 1a of a desk main body 1 and a frame body 3b fixed to the lower surface of the upper plate part 3a is vertically movably and pivotally supported to the desk main body 1, an elevating and lowering body 9 is vertically movably disposed inside the desk main body 1 facing the storage box 3, a sprocket wheel 11a is rotatably pivotally supported to the elevating and lowering body 9, and one end of a chain 11b wound to the sprocket wheel 11a is connected to the desk main body 1. Then, the other end part of the chain 11b is connected to the storage box 3, a gas spring 10 for energizing the elevating and lowering body 9 upwards is provided and a locking means 12 to be attachably and detachably engaged with the storage box 3 pushed down against the gas spring 10 and an unlocking means 13 for unlocking the lock of the locking means 12 are provided.