To provide a desk for which an attachment part can be decorated by a cover body without damaging working efficiency when attaching and detaching a desktop option such as a desktop panel to/from a top plate.

When a part of a frame structure A supporting the top plate 4 is formed as a base 5, the base end of the desktop panel 6 which is the desktop option is made attachable from above to an attaching area B1 set to the base 5, and the base 5 is configured to be covered with the cover body C capable of changing a form according to the kind of the desktop option such as the desktop panel 6 and its presence/no presence, the cover body C is fixed to the base 5 at a position evading at least the attaching area B1 of the desktop panel 6 which is the desktop option and a state opened upwards is taken without narrowing the attaching area B1 in the middle.