A method for manufacturing metal powder includes: melting at least a portion of a metal starting material in a reaction vessel by utilizing plasma so as to form molten metal; evaporating the molten metal so as to produce a metal vapor; and transferring the metal vapor from the reaction vessel to a cooling tube together with a carrier gas supplied into the reaction vessel so as to cool the metal vapor, and condensing the metal vapor in the cooling tube, thereby producing metal powder. The method further includes supplying an oxygen gas into the reaction vessel.