A magnetoresistive effect element according to the present invention includes: a first ferromagnetic layer as a magnetization fixed layer; a second ferromagnetic layer as a magnetization free layer; and a nonmagnetic spacer layer provided between the first ferromagnetic layer and the second ferromagnetic layer. The nonmagnetic spacer layer comprises an Al alloy represented by General Formula (1), and thereby lattice mismatch between the nonmagnetic spacer layer and the first ferromagnetic layer and/or the second ferromagnetic layer is reduced, compared to lattice mismatch when the nonmagnetic spacer layer is formed of Al. AlγX1-γ  (1) [wherein, X indicates one element selected from the group consisting of Li, N, Mg, Si, Sc, Cr, Fe, Ni, Cu, Zn, Ga, Ge, Zr, Ru, Pd, Ag, Sn, W, Pt, Au and Th, and γ is 0.5