This paper presents the construction of a probe for immittance spectroscopy.The probe is based on the four-electrode technique. The current applicationelectrodes are long parallel strips and have been partitioned into three segmentsto measure the immittance of relatively small volumes. The probe constanthas been calculated assuming anisotropy of the materials examined. Theexperiments, based on the measurements of KCl solutions and numericalsimulations (finite element method—FEM), have shown a high degree ofconsistency with the theoretical value. Experimental in vivo measurementson swine gluteal tissue were performed and the conductivity and permittivityreconstructed from these measurements are presented.