Abstract: Provided is an alloy powder capable of obtaining a magnetic member therefrom in which the frequency FR is extremely high. The powder for the magnetic member is composed of a plurality of flaky particles. These flaky particles are composed of an Fe-based alloy including: 6.5% by mass or more and 32.0% by mass or less of Ni; 6.0% by mass or more and 14.0% by mass or less of Al; 0% by mass or more and 17.0% by mass or less of Co; and 0% by mass or more and 7.0% by mass or less of Cu; the balance being Fe and unavoidable impurities. The average thickness Tav of this powder is 3.0 ?m or less. The saturation magnetization Ms of this powder is 0.9 T or more. The coercive force iHc of this powder is 16 kA/m or more. This Fe-based alloy has a structure resulting from spinodal decomposition.