An example magnetoresistive effect element includes a magnetoresistive
effect film including a magnetization pinned layer, a magnetization free
layer, and an intermediate layer interposed therebetween and having a
magnetic region and a nonmagnetic region whose electrical resistance is
higher than the magnetic region. A sense current is passed to the
magnetoresistive effect film in a direction substantially perpendicular
to the film plane thereof. The magnetic region of the intermediate layer
penetrates the nonmagnetic region locally and extends in the direction
substantially perpendicular to the film plane. The nonmagnetic region
contains a nonmagnetic metallic element having a larger surface energy
than a magnetic metallic element contained in the magnetic region.