Device for detecting defects in multilayer structures composed of layers of ferromagnetic bars or wires having different orientations. The device comprises first magnetic means suitable for generating, in the upper layer, a magnetic field following the orientation of the magnetic wires of the upper layer and as many magnetic means as there are lower layers located above the layer to be inspected, each magnetic means being assigned to a lower layer and being suitable for generating, in said lower layer, a magnetic field following the orientation of the magnetic wires of said assigned layer. The device comprises electromagnetic field emitting/receiving means arranged above the upper layer, and suitable for emitting an electromagnetic field in the layer to be inspected and for receiving, in response, signals representative of the state of the magnetic wires in the layer to be inspected.
