Due to the vertiginous increase of the electromagnetic emissions of the modern communication systems and to the affected population's concern, it becomes necessary a more exhaustive control of this type of contamination. There are available different measure devices that make a characterization of the received emissions, but most does not discriminate between the contributions from different systems. Therefore, you cannot identify the systems responsible for the excessive measured levels. Of all the studied devices, the one that better it fulfils the expectations it is the spectrum analyzer, that it allows to characterize the received emissions, separating the different bands of the spectrum, and isolating the frequencies that don't perform the existent norm. To control the spectrum analyzer we have developed a software program that makes the measures according to the procedure exposed in the standard. Finally, another program processes and it represents the results of the measures. In addition, this application can calculate the theoretical level of radiation of different communication systems by simulation approximations and then, to compare with the measurement levels and with the reference level.