Provided is iron-based metal powder for powder metallurgy including a metallic soap containing at least one or more types of metal selected from a group of Ag, Au, Bi, Co, Cu, Mo, Ni, Pd, Pt, Sn and Te having a higher standard oxidization potential than iron, and an additional metal which forms a liquid phase at a temperature of 1200.degree. C. or less in the combination with the metal, wherein the soap contains metal for forming an alloy phase between the two. As a result, obtained is mixed powder for powder metallurgy capable of improving the rust prevention effect easily without having to hardly change the conventional processes.