PURPOSE: To make it possible to enhance the volumetric ratio of alloy powder using the magnetic alloy powder which is formed into the prescribed grain diameter in an inert gas atmosphere using an atomizing method.

CONSTITUTION: The metal, which is compounded so as to become RCO5 of R2TM17, is dissolved in a vacuum atmosphere, thermoplastic resin powder is mixed into the magnetic alloy powder having average grain diameter of 5 to 50μm obtained by treating the above-mentioned fused alloy in an inert gas atmosphere using an atomizing method, the alloy powder is kneaded under heat, and composite resin pellet formed by mixing resin into magnetic alloy powder can be obtained. As the fludity of this powder itself is more excellent than the mechanically pulverized powder, the use of a small quantity of thermoplastic resin is enough, and the mixing quantity of magnetic alloy powder can be increased. As a result, the volumetric ratio of the magnetic alloy powder can be enhanced up to 75% in the volumetric ratio of the thermoplastic resin and the magnetic alloy powder.