A magnetoresistance effect element includes a free layer as a first ferromagnetic layer, a pinned layer as a second ferromagnetic layer, and at least one nano-junction provided between the free layer and the pinned layer. The nano-junction contains at least one non-metal selected from the group consisting of oxygen, nitrogen, sulfur and chlorine. Preferably, the material for forming the nano-junction is a ferromagnetic metal selected from the group consisting of Fe, Ni, Co, NiFe, CoFe and CoFeNi or a halfmetal selected from the group consisting of NiFeSb, NiMnSb, PtMnSb and MnSb.