A new experimental method for the analysis of current-potential curves determined with a scanning tunneling microscope in an electrochemical cell is described. Spectroscopic measurements have been performed in sulfuric acid at a tungsten diselenide semiconductor sample. Measurements of current-voltage curves obtained with the STM for different tunneling gaps and for different potentials of the tip and the semiconductor are recorded, and results are shown. Current-distance curves obtained from these measurements allow the separation of the influence of the tunneling barrier from that of the Schottky barrier at the semiconductor/electrolyte interface. Changes in the barrier heights are due to an electronic influence from the tip potential on the semiconductor surface potential when the tip enters the electrochemical double layer.