Thin film magnetic element having a pair of first soft magnetic layers sandwiching a magnetoresistive effect film and a coil windingly formed about a second soft magnetic layer

A thin film magnetic element, comprising:

• a magnetoresistive effect film provided with (i) a magnetization fixed layer and (ii) a magnetization free layer via a non-magnetic spacer layer therebetween;
• a pair of electrodes arranged via the magnetoresistive effect film in a lamination direction of the magnetoresistive effect film;
• a pair of first soft magnetic layers that are separated from the magnetoresistive effect film and are arranged opposite to each other so as to sandwich the magnetoresistive effect film;
• a second soft magnetic layer that is more separated from the magnetoresistive effect film than each of the first soft magnetic layers is separated from the magnetoresistive effect film, a part of the second soft magnetic layer being arranged opposite to the pair of first soft magnetic layers in the lamination direction;
• and
• a coil that is windingly formed about the second soft magnetic layer,
• wherein when a rear end region cross-sectional area of the first soft magnetic layers is defined as S1r and a tip end region cross-sectional area of the second soft magnetic layer is defined as S2f, a relationship of S2f>S1r is satisfied, and when a tip end width of the first soft magnetic layers is defined as W1f and a rear end width of the first soft magnetic layers is defined as W1r, a relationship of W1r>W1f is satisfied.