Magneto-resistive effect device and magnetic disk system with refilled insulation layer in contact with a read end face of a cap layer

The invention provides a giant magneto-resistive effect device (CPP-GMR device) having a CPP (current perpendicular to plane) structure comprising a multilayer device assembly comprising a fixed magnetization layer, a spacer layer, a free layer and a cap layer stacked one upon another in order, with a sense current applied in a stacking direction of the multilayer device assembly. In the rear of the multilayer device assembly, there is a refilled insulation layer formed, which is in contact with the rear end face of the multilayer device assembly and extends rearward, wherein the uppermost position P of the refilled insulation layer that is in contact with the rear end face of said multilayer device assembly lies at a rear end face of the cap layer and is set in such a way as to satisfy a relation: 0.2≦(T2/T1)