A soft magnetic alloy used as a radio frequency magnetic material and having high resistivity and high magnetic permeability in a high frequency band, and an inductor, a wave absorber and antenna each comprising the soft magnetic alloy. The soft magnetic alloy has a crystal phase containing Co as a main component and at least one element T selected as a primary component from Fe, Ni, Pd, Mn and Al, and having a face-centered cubic structure, a body-centered cubic structure or a mixture thereof having an average crystal grain size of 30 nm or less; and a ferromagnetic amorphous phase surrounding the crystal phase and containing at least one element M selected from Ti, Zr, Hf, Nb, Ta, Mo, W, Y and rare earth elements, O, N, C, B, at least one oxide of element M, Fe and element T.