A magnetoresistance effect element, comprising a nonmagnetic spacer layer,
first and second ferromagnetic layers separated by the nonmagnetic spacer
layer, the first ferromagnetic layer having a magnetization direction at
an angle relative to a magnetization direction of the second
ferromagnetic layer at zero applied magnetic field, the magnetization of
the first ferromagnetic layer freely rotating in a magnetic field signal,
a magnetoresistance effect-improving layer comprising a plurality of
metal films and disposed in contact with the first ferromagnetic layer so
that the first ferromagnetic layer is disposed between the nonmagnetic
spacer layer and the magnetoresistance effect-improving layer, one of the
plurality of metal films disposed in contact with the first ferromagnetic
layer contains metal element of not solid solution with metal element of
the first ferromagnetic layer and a nonmagnetic underlayer or a
nonmagnetic protecting layer disposed in contact with the
magnetoresistance effect-improving layer so that the magnetoresistance
effect-improving layer is disposed between the first ferromagnetic layer
and the nonmagnetic underlayer or the nonmagnetic protecting layer.