PURPOSE: To provide a method for manufacturing a dental prosthesis capable of preventing the breakage of a dental prosthesis resulted from a scratch generated at the time of cutting and polishing the sprue line of a casted material.

CONSTITUTION: A sprue line 12 is planted on the cheek side surface 13 of a wax pattern 11. A casting mold is formed by use of the wax pattern 11. Into the obtained casting mold, glass ceramics is casted. Thereafter, heating treatment is conducted with determined temperature and time, and the glass ceramics is crystallized to provide a casted material having a wax pattern part having the form corresponding to the wax pattern 11 and a sprue line part having the form corresponding to the sprue line 12. After the sprue line part of the casted material is cut and polished, porcelain having a thermal expansion coefficient nearly equal to that of the glass ceramics is baked so as to cover the surface area of the wax pattern part to which the sprue line part is connected, and a dental prosthesis is provided.