An iron alloy powder consists of, when the entirety thereof is assumed to be 100 mass%, Cr: 2.5 mass% to 3.5 mass%, Mo: 0.4 mass% to 0.6 mass%, and Fe and inevitable impurities as the balance, a mixed powder consisting of 15 mass% to 40 mass% of the iron alloy powder, 1.2 mass% to 1.8 mass% of a copper powder, 0.5 mass% to 1.0 mass% of a graphite powder, and a pure iron powder as the balance when the entire mixed powder is assumed to be 100 mass% is compacted into a compact, and the compact is sintered while transforming a structure derived from the pure iron powder into a structure in which a ferritic structure and a pearlitic structure are mixed and transforming a structure derived from the iron alloy powder into a martensitic structure.