An MR device includes a magnetization pinned film having a nonmagnetic
intermediate layer positioned on the opposite side of a magnetization
free layer while sandwiching a nonmagnetic spacer layer and made of RuCu.
In the case of passing read current in the stacking direction via lower
and upper electrodes, decrease in a resistance change amount caused by a
second magnetization pinned layer can be suppressed. Further, a first
magnetization pinned layer and the second magnetization pined layer which
are thicker can be antiferromagnetically coupled to each other in
magnetic fields in a wider range. Thus, both increase in the resistance
change amount and magnetic field stability can be achieved. Therefore,
while maintaining stable operations by reducing the influence of external
noise, the invention can address higher recording density by the increase
in the resistance change amount as a whole.