The invention provides a giant magneto-resistive effect device (CPP-GMR device) having a CPP (current perpendicular to plane) structure comprising a spacer layer, and a fixed magnetized layer and a free layer stacked one upon another with said spacer layer interleaved between them, with a sense current applied in a stacking direction, wherein the spacer layer comprises a first and a second nonmagnetic metal layer, each formed of a nonmagnetic metal material, and a semiconductor oxide layer interleaved between the first and the second nonmagnetic metal layer, wherein the semiconductor oxide layer that forms a part of the spacer layer is made of indium oxide (In.sub.2O.sub.3), or the semiconductor oxide layer contains indium oxide (In.sub.2O.sub.3) as its main component, and an oxide containing a tetravalent cation of SnO.sub.2 is contained in the indium oxide that is the main component. The semiconductor oxide layer that forms a part of the spacer layer can thus be made thick while the device has a low area resistivity as desired, ensuring much more favorable advantages: ever higher MR performance, prevention of device area resistivity variations, and much improved reliability of film characteristics.