PURPOSE: To provide a new type binder for kneading metal powder or ceramic powder for obtaining the sintering shaped part with uniform density by injection molding, extrusion and other mechanical molding techniques.

CONSTITUTION: The binder is called as polymer solid solution and it is constituted of a major fraction of low molecular weight solid chemical substance as a solvent and at least one type of a minor fraction of high molecular weight solid polymer as a solute. The latter is substantially dissolved in the solvent. The polymer solid solution binder is uniformly mixed with known metal/ceramic powder, it easily flows and it maintains a given form after solidification. Then, the binder is removed by the advantageous debinding processes having two stages, namely, the selective extraction of solid chemical substance, a solvent extraction method and a sublimation method, for example. The solid chemical substance maintains solidity during that time and the amount of the polymer does not change. Then, the binder is removed by the heating of the polymer for obtaining the mold for sintering.