A desk apparatus is provided with a pair of leg members, each having two main leg member parts that are installed on a floor surface and extend in a vertical direction and that are connected to each other by means of a crosspiece portion at upper portions of the main leg member parts, and a pair of inner connecting rods and a pair of outer connecting rods that extend along a width direction and connect the upper portions of the pair of leg members. The inner connecting rods are connected together by bridge members so as to constitute connecting units. The connecting units are attachable to and detachable from a top plate support, and a first top plate unit is attachable to and detachable from the top plate support. This allows for the provision of a desk apparatus in which the first top plate unit and the connecting units are replaceable with different top plate units and different connecting units, and the aspects of the desk apparatus can be changed in accordance with a user's demands by keeping replacement of members to a necessary minimum.