A method for producing a soft
magnetic alloy ribbon having a composition represented by Fe100−x−y−zAxByXz, wherein A is Cu and / or Au, X is at least one element selected from the group consisting of Si, S, C, P, Al, Ge, Ga and Be, and x, y and z are numbers (by atomic %) meeting the conditions of 0<x≦5, 10≦y≦22, 1≦z≦10, and x+y+z≦25, and comprising a matrix phase in which fine
crystal grains having an
average diameter of 60 nm or less are dispersed at a
volume fraction of 50% or more, part of an
oxide film formed on the surface being a layer having a lower B concentration than the average B concentration of the matrix phase; comprising the steps of (1) ejecting an
alloy melt having the above composition onto a rotating cooling roll for
quenching, to form a primary fine-crystalline
alloy ribbon having a matrix phase, in which fine
crystal nuclei having an
average diameter of 30 nm or less are dispersed at a
volume fraction of more than 0% and less than 30% in an
amorphous phase; and then (2) annealing the primary fine-crystalline
alloy ribbon in an
atmosphere having an
oxygen concentration of 6-18%.