Write characteristics and read characteristics can be improved at the same time by applying novel materials to ferromagnetic layers. In a magnetoresistive effect element having a pair of ferromagnetic layers being opposed to each other through an intermediate layer to cause a current to flow in the direction perpendicular to the film plane to obtain a magnetoresistive change, at least one of the ferromagnetic layers contains a ferromagnetic material containing Fe, Co and B. The ferromagnetic material should preferably contain Fe.sub.aCo.sub.bNi.sub.cB.sub.d (in the chemical formula, a, b, c and d represent atomic %. 5.ltoreq.a.ltoreq.45, 35.ltoreq.b.ltoreq.85, 0