PURPOSE: To improve the wear resistance and effective permeability of an Ni- Fe-Nb alloy by adding a small amount of N to the alloy.

CONSTITUTION: An alloy consisting of, by weight, 70W86% Ni, 0.5W10% Nb, 0.0003W0.3% N, 0.01W7% in total of ≥1 kind of element selected from ≤7% each of Mo, W, Ta, Mn, Cu and Co, ≤5% each of Cr, V, Ti, Ge, Ga, In and Tl, ≤3% each of Al, Si, Zr, Hf, a rare earth element and a Pt group element and ≤2% each of Be, Sn, Sb and B, a small amount of impurities and the balance Fe is heated at 600°CW the m.p. in a nonoxidative atmosphere or a vacuum for a suitable time of about 1minW100hr corresponding to the composition. The heated alloy is cooled from a temp. above the regular-irregular lattice transformation point at a suitable cooling rate of about 100°C/secW1°C/hr corresponding to the composition. The cooled alloy is further heated at a temp. below said transformation point in a nonoxidative atmosphere or a vacuum for a suitable time of ≥ about 1min corresponding to the composition, and it is cooled to obtain an alloy with ≥5,000 saturation magnetic flux density.