Thin film permeability measurement techniques such as stripline cavities or conventional permeameters require the sample undergoing measurement to be inserted within a fixture; typically, these samples can be no larger than a few square inches. However, certain applications require knowledge of the complex permeability of a coating or film applied to a finished, large product such as films deposited onto a continuous web for use as identification markers, the inside of a computer case for the control of EMI, or a ship mast for reduction of radar reflections. Therefore, a surface permeameter is presented that measures the rf complex permeability spectra of continuous films or coatings that are placed adjacent to the fixture over the frequency range of 10–500 MHz. ©1996 American Institute of Physics.