To prevent an electrical cord from becoming obstructive by considering much about the structure of the top plate part of a desk, a table, etc., to be used with an OA apparatus, etc., placed thereon and to allow the top plate to have diversity and convenience by adding a function according to like of each person.

By arranging and fixing a plurality of blocks of a prescribed area having a space part into which the electrical cord is inserted, formed on the side of a lower surface on the top plate of the desk, etc., a new top plate part is formed on the top plate of the desk. It is convenient to add various kinds of functions such as a plug socket, a recess part for housing small articles to these blocks. These blocks can simply be fitted by using fixing means such as a Hook-and-Loop fastener, a sucker sheet.