A base for a dental working model includes divided plates (2) made of plastic mixed with plaster or the like and a support base (3) having openings into which the pins (14) of the divided plates (2) are fitted and made of a plastic different from that of the divided plates (2). On the joint surface between the divided plates (2) used by attaching a plaster impression model (1) thereto and the support base (3), openings that allow a plaster saw (9) to enter are provided. Two steps, including a step (B) of sawing down from the top and a step (A) of sawing up from the bottom of the divided plates (2), enables a cut by which the area of the joint surface is reliably secured as the base surface (C1) of an abutment tooth (C) and therefore enables a highly accurate prosthetic appliance (7) to be made.
