This final project had as its objective the development of a system capable of automating the process of characterization of GMI (Giant Magnetoimpedance) samples. With this, the GMI effect of the sample is explored aiming the rapid determination of the optimal point of operation and, consequently, of its use as a magnetometer. Seeing as there are many parameters that affect the performance of these devices, such as the DC and AC levels of excitement currents, and respective frequency, the disposition of the magnetic field, among others, the advantage of an automatic system of the characterization of the impedance of the ribbons is evident. Developed in LABVIEW, and using auxiliary analysis tools written in Perl, the most conservative estimations for the execution time of various experiments using the developed system indicate a decrease of about 10 times the time spent in manual measurements. Also developed was an optimization process of the sensibility of the GMI samples in relation to the frequency of the excitement current. For a certain configuration, in relation to the absolute value of the sensibility, an unstable global maximum was observed, as well as a local one, much more stable but with lightly reduced amplitude.