PURPOSE: To eliminate the deformation of a finished product of complicated shape by inserting a core insert formed of an organic material with a molding cavity into a die, then injection-molding a compound containing a metal powder into the cavity part and sintering a molding taken out of the die after degreasing it at a temperature at which the core insert can be decomposed.

CONSTITUTION: A core insert formed of an organic material 2 with a molding cavity part 1 formed is introduced into a die 4. Further a compound containing a metal or ceramic powder which is decomposable at a higher temperature causing the main component of a binder to decompose than that causing a UV-curable resin used for the core insert 2 to decompose and which is fusable at a lower temperature causing the binder to fuse than that causing the UV- curable resin to decompose, is injected into the cavity part 1 to form a molding 6. Further, both molding 6 and core insert 2 are taken out of the die and degreased. Consequently, the core insert 2 decomposes and a degreased product 7 shaped like the molding 6 is obtained, and is sintered. Thus the sintered product 8 of complicated shape can be produced.