Permittivity measurement of foams and other soft materials poses several difficulties. E.g., the permittivity of such material is usually low in value and is strongly dependent on the compression-ratio, atmospheric humidity, etc. Furthermore, the thermal expansion of the materials used to construct the probe, i.e., the temperature dependency can affect the measurement. In this paper we present a measurement setup for permittivity measurement of foams in the frequency range of up to several MHz. Results for a test material are reported and analyzed with respect to temperature, humidity and compression-ratio dependency. The measurement uncertainty of the probe has been investigated by means of a theoretical analysis within a finite element simulation framework. ©2010 IEEE.