Interferometric measuring method and device for measuring the shape of or the distance to surfaces

An interferometric measuring method and device for measuring the shape of, or the distance to, surfaces are provided, in which light is generated, modulated with respect to its frequency, conducted to both an object surface and a reference surface, brought to interference, and conducted to a photodetector, and, to detect the particular distance, a phase of the photodetector signal is evaluated. A simple, rugged configuration, with the capability of taking a high-resolution measurements in the context of a large unambiguity range, is achieved in that the phase is considered in at least two different instants with the wavelengths that correspond on the basis of the frequency modulation, and the results are fed to the evaluation.