A thin film magnetic element is disclosed which uses a soft magnetic thin film having a composition represented by the general formula: T.sub.100-x-y M.sub.x (AO.sub.v).sub.y (wherein T stands for at least one element selected from the group consisting of Fe and Co, M for at least one element selected from the group consisting of Zr, Hf, Nb, and Y, and A for at least one element selected from the group consisting of Si, Ge, Sn, B, P, and C, and x, y, and v respectively satisfy the expressions, 5.ltoreq.x.ltoreq.20 at. %, 8.ltoreq.y.ltoreq.25 at. %, and 0.ltoreq.v.ltoreq.2), consisting of a homogeneous amorphous phase, and having resistivity of not less than 1000 .mu..OMEGA..multidot.cm. Further, a thin film magnetic element is disclosed which uses a soft magnetic thin film of a microstructure having a composition substantially represented by the general formula, T.sub.100-x-z M.sub.x (AO.sub.v).sub.z (1.ltoreq.z.+-.10 at. %) and consisting of a microcrystalline phase and a first amorphous phase and a second amorphous phase disposed around the phases mentioned above.