The invention relates to a manufacturing method of fixing material for surgery. In a manufacturing method of fixing material made of a substrate made of resin components and metal thin sheet of thermally conductive powder and having higher thermal conductivity than the resin, principle heat conduction performance is maintained and odd smell can be reduced. The manufacturing method comprises a metal flakes preparation process of preparing metal flakes which are produced by flakes-izing metallic powder under wet conditions in which a first organic solvent exists using a flakes-ized auxiliary agent and in which a flakes-ized auxiliary agent adhered to the surface, a molding process of mixing metal flakes and the aforementioned resinous principle and molding a substrate, composition which is an organic solvent which does not contain aromatic series system hydrocarbon is used for a first organic solvent that a flakes-ized auxiliary agent which it has even if small, and is used in the aforementioned metal flakes preparation process is univalent unsaturated fatty acid with a carbon number of 12 or more, or uses in the aforementioned metal flakes preparation process.