To preserve excellently the needle-like shape of fine metal magnetic powder and to make the magnetic characteristics of the metal magnetic powder enhanced by a method wherein a specified non-reducing gas is mixed in a reducing atmosphere to perform a heating treatment on needle-like fine powder containing an iron oxyhydroxide as its main content and thereafter, the fine powder is performed a deoxidation treatment.

This metal magnetic powder is manufactured by a method wherein needle-like fine powder containing an iron oxyhydroxide as its main content is performed a heating treatment in a reducing atmosphere, and after this, the fine powder is performed a deoxidation treatment. In this case, non- reducing gas of an atomic number 7 or more is mixed in this reducing atmosphere to perform the heating treatment. It is preferable that the non-reducing gas of the atomic number 7 or more is one kind of the gas of at least either of the two kinds of the gases, which are chosen from a group consisting of N2, Ne, Ar, Kr, Xe and Rn gases. Moreover, as the iron oxyhydroxide, an α-FeOOH, a β-FeOOH, a γ-FeOOH and the like are exemplified and specially, the α-FeOOH and, a γ-FeOOH are preferable.