A spin-valve device of a CPP structure which has a high resistance, and which generates a high output signal with low current. The CPP spin-valve device including a spin-valve element having a substrate and a layered structure formed on the substrate. The layered structure includes a first thin film layer of ferromagnetic material, a second thin film layer of ferromagnetic material, and a thin non-magnetic layer structure separating the first and second layers. One of the first and second thin film layers is defined as a free layer and the other layer is defined as a pinned layer, where the free layer has a direction of magnetization that is easier to change than a direction of magnetization of the pinned layer by application of a magnetic field. The non-magnetic layer structure includes a conducting part and insulating part, with the conduction part having an area that is smaller than an area of the free layer. The device further includes a device for producing a current flow through the spin-valve element and a field sensor configured to sense variations in resistance of the spin-valve element due to a difference in rotation of the magnetizations in the free layer and the pinned layer caused by an applied magnetic field.