Non-destructive methods of measurement for determining the thickness of thin layers, using the magneto-inductive method or the eddy-current method yield measured values which depend not only on the actual layer thickness present, but also on the shape of the measured object. It is the object of the invention to specify in a simple way, and without it being necessary for an operator to change his way of thinking, a device and a method in accordance with which the layer thickness indicated is virtually independent of the shape of the measured object. With regard to the device, this is achieved according to the invention when the probe has at least two different coil devices and, with regard to the method, when a corrected layer thickness is calculated from the different measured values of the two coil devices.