A probe unit having a coaxial structure and including a probe electrode, a guard electrode and a contacting module arranged on a section of the probe electrode, which contacting module including an insulating sleeve, a flexible circuit board with a first conduction path for the electrical contacting of the probe electrode and a second conduction path for the electrical contacting of the guard electrode, and a module housing, wherein a first contact plate is provided that electrically contacts the first conduction path, the module housing including a second contact plate that electrically contacts the second conduction path, wherein the module housing has a pot-shaped geometry with a cylindrical wall, which wall substantially surrounds, protects and/or electromagnetically shields at least the probe electrode in the region in which the contacting module is arranged, at least a part of the insulating sleeve, and at least sections of the circuit board.