A sinter of stable quality is produced by molding a powder for powder metallurgy. This process includes successively conducting the following steps: charging a powder and a solid lubricant into a mold compact formation in which the powder charged into the mold is compacted; releasing the compact from the mold; and the powder for powder metallurgy is charged again into the mold after the release step. The temperature of the mold is set at a value in the range of from the boiling point of water to the melting point of the solid lubricant. The compact can be continuously formed without causing, e.g., a failure in the feeding of the powder for powder metallurgy. The sinter obtained by sintering the compact is almost even in strength and density.