To solve the problems that liquid chemicals scatter on a work table, treatment implements touch the work table, the work table is stained and it is not sanitary during use while treatment is performed by placing various liquid chemicals and treatment implements on the work table at the time of dental treatment.

Figure (A) is a schematic perspective view indicating one example of the work table, and Figure (B) is a perspective view indicating one example of a cover member. The cover member 10 is formed of thin thickness synthetic resin or paper, the inner surface shape of a lower part matches with the upper surface shape of the work table 2 (or 4) indicated in Figure (A), and it is formed so as to be entirely fitted to the work table at the time of being put on from the above of the work table 2 (or 4). By exchangeably attaching the cover member 10 to the dental work table 2 (or 4), the work table is maintained just by exchanging the cover member, and thus it is sanitary.