The present invention relates to a metal powder containing: 0.001 mass% ≤ C ≤ 0.45 mass%, 0.01 mass% ≤ Si ≤ 3.50 mass%, Mn ≤ 2.0 mass%, 7.5 mass% ≤ Cr ≤ 21.0 mass%, 1.5 mass% ≤ Ni ≤ 7.0 mass%, Mo ≤ 1.3 mass%, 0.05 mass% ≤ V ≤ 2.0 mass%, Al ≤ 0.015 mass%, and N ≤ 0.20 mass%, with the balance being Fe and unavoidable impurities, satisfying 0.05 mass% ≤ C+N ≤ 0.58 mass%, and satisfying: 10 eq /Ni eq eq = Cr+Mo+1.5Si+0.5Nb, and Ni eq = Ni+30C+30N+0.5Mn.