The characteristics and the electronic circuit of an automatic test set which can perform the measurement of doping profile of a semiconductor epitaxial layer are reported. The doping profile presentation is on an X‐Y plotter. The technique used is that of realizing a Schottky barrier on the epitaxial film and of measuring the capacitance and its derivative vs the reverse voltage applied to the junction. An analog elaboration of this information, according to the Schottky barrier diode equations, finally gives the desired doping profile. Experimental results on different epitaxial layers are reported. If the geometrical dimensions of the Schottky barrier diode are known, an absolute calibration of the carrier concentration is possible.