A calibration method for a CD-SEM technique, includes determining a match function converting at least one parameter obtained by modelling a measurement supplied by the CD-SEM technique into a function of at least one parameter representative of a measurement supplied by a characterisation technique different from the CD-SEM technique, the match function being characterised by a plurality of coefficients; performing measurements on a plurality of patterns chosen to cover the desired validity range for the calibration, the measurements being done using both the CD-SEM technique to be calibrated and the reference technique; determining, from the measurements, a set of coefficients of the match function minimising the distance between the functions of the parameters measured using the reference technique and applying the match function to the parameters obtained by modelling measurements supplied by the CD-SEM; using the set of coefficients during the implementation of the calibrated CD-SEM technique.