A magneto-resistive element according to an aspect of the present
invention includes a free layer whose magnetized state changes and a
pinned layer whose magnetized state is fixed. The free layer comprises
first and second ferromagnetic layers and a non-magnetic layer which is
arranged between the first and second ferromagnetic layers. An intensity
of exchange coupling between the first and second ferromagnetic layers is
set so that an astroid curve in a hard axis direction opens.