A magnetoresistance effect element includes first and second magnetic layers having a perpendicular magnetization direction, and a first non-magnetic layer disposed adjacent to the first magnetic layer and on a side opposite to a side on which the second magnetic layer is disposed. An interfacial perpendicular magnetic anisotropy exists at an interface between the first magnetic layer and the first non-magnetic layer, and the anisotropy causes the first magnetic layer to have a magnetization direction perpendicular to the surface of the layers. An atomic fraction of all magnetic elements to all magnetic and non-magnetic elements included in the second magnetic layer is smaller than that of the first magnetic layer.