A FEM simulation program for induction hardening of sintered metal shafts was made up. Physical properties of the sintered metal were measured. An electromagnetic field analysis, a heat conduction analysis and an elastic-plastic stress analysis during the induction hardening process of sintered metal shafts were carried out for various hardening conditions by using the measured material data and the simulation program. The effects of the electric power and the frequency on the temperature and the stress during the induction hardening process of the sintered metal shaft and the residual stress were examined. The map for selecting the optimum heating condition (P, f) for the residual stress of the sintered metal shaft due to the induction hardening was indicated.