Apparatus for measuring the local electrical resistance of a surface, the apparatus comprising: a DC voltage source for applying a bias voltage (Vpol) to the sample (E) for characterizing; a measurement circuit (CM) capable of being connected to a conductive probe suitable for coming into contact with a surface (SE) of said sample in order to generate a signal (S) representative of a contact resistance between said conductive probe and said surface of the sample; and a control device (CMD) for controlling said measurement circuit; the apparatus being characterized in that said measurement circuit comprises: a measurement resistive two-terminal network (DM) presenting variable resistance and connected between said conductive probe and a ground of the circuit; and a calculation unit (UC) for generating said signal representative of a contact resistance between said conductive probe and said surface of the sample as a function of a voltage (Vs) across the terminals of said measurement resistive two-terminal network.