Abstract: The present invention relates to a needle-like probe (1) for use in electrical potential sensing and RF ablation of tissue, a method of making such probes (1), and a probe array comprising a number of such probes (1). The probe (1) has an elongated body (2, 22) with one end (9,29) adapted for penetration of tissue. The body (2, 22) has sufficient rigidity to be inserted into the tissue. The elongated body (2, 22) also comprises two or more electrodes (7, 27) separated and spaced apart from each other along the elongated body (2, 22) by insulative material (8, 28). Each electrode (7, 27) has at least one electrical conductor (10, 11) coupled to the electrode (7, 27). The electrode (7, 27) is capable of delivering RF energy to the tissue surrounding the electrode (7, 27) and sensing the electrical potential of the tissue.