PURPOSE: To shorten the molding time and improve production efficiency by composing an original shape of a circular part of a base and a film layer formed integrally on its own surface, forming one gate at the center of the film layer and injection molding the original shape out of the gate.

CONSTITUTION: An original shape 2a of a circular ceramic part l is composed of a base 3a comprising ceramic as its main raw material and a film layer 5 formed integrally on its one surface, and a gate 9 is formed directly at the center of the film layer 5, and an original shape 2a omitting a runner R is injection molded. Said original shape 2a is burnt to form a sintered body 6a, and then the film layer 5 is removed from the sintered body 6a. As for the ceramic constituting the original shape, the ceramic of ferrite family, aluminum family, zircon family, magnesium titanate family or the like is used, and for example, synthetic resin powder, silicon powder or the like is mixed therein as a fluid upgrading material. The thickness (t) of the film layer 5 to be molded integrally on one surface of the base 3 is desirably in the range of 0.1-0.5mm.