A magnetoresistive device of a CPP (current perpendicular to plane) structure includes a magnetoresistive unit sandwiched between a first substantially soft magnetic shield layer from below, and a second substantially soft magnetic shield layer from above, with a sense current applied in a stacking direction. The magnetoresistive unit includes a non-magnetic intermediate layer sandwiched between a first ferromagnetic layer, and a second ferromagnetic layer. At least one of the first and second shield layers is configured in a window frame of a planar shape, including a front frame-constituting portion and a back frame-constituting portion partially comprising a combination of a nonmagnetic gap layer with a bias magnetic field-applying layer. The combination of the nonmagnetic gap layer with the bias magnetic field-applying layer forms a closed magnetic path with magnetic flux going all the way around the window framework, turning the magnetization of the front frame-constituting portion into a single domain.