Based upon the standard IEEE 1309, a new calibration method for electromagnetic (EM) probes is proposed. The aforementioned method compares the electric field strength measured with the EM probe subject to calibration with the E-field intensity calculated through a linear interpolation of the corrected measurement using a reference EM probe. The corrected measurement results are computed by means of the calibration factors stated in the calibration certificate of the reference EM probe. The conditions and criteria, under which it is possible to calibrate EM probes inside semi-anechoic chambers in the frequency range of 80 MHz to 1 GHz, are presented. The results shows that the calibration method proposed in this paper is characterized by deviations less than 1 dB in almost all the frequencies considered, verifying the reliability of the method. The proposed approach is very useful for registering the measurement drift of EM probes used in EMC testing laboratories