A highly sensitive method of obtaining the permeability of a magnetic film without limitations in sample size was developed based on the skin effect of magnetic film in the vicinity of a microstrip line probe. The permeability of a (Co25Fe75)90B10 thin film (45 x 25 mm, and 0.53 μm thick) was optimized in a frequency range from 10 MHz - 17 GHz; the measured values roughly corresponded to those obtained with the Landau-Lifshitz-Gilbert equation. We analyzed the upper frequency limitations of the permeability measurements using a meander probe, then the impedance mismatching may limit the upper frequency.
