Beams of Carbon nuclei are used or planned to be used invarious centers for cancer treatment around the world because of theirtherapeutic advantages over proton beams. The knowledge of thefragmentation of Carbon nuclei when they interact with the human bodyis important to evaluate the spatial profile of their energydeposition in the tissues, hence the damage to the tissues neighboringthe tumor. In this respect, the identification of the fragmentationproducts is a key element. We present in this paper the chargemeasurement of about 3000 fragments produced by the interaction of12C nuclei with an energy of 400 MeV/nucleon in a detectorsimulating the density of the human body. The nuclear emulsiontechnique is used, by means of the so-called Emulsion CloudChamber. In order to achieve the large dynamical range required forthe charge measurement, the recently developed techniques of theemulsion controlled fading are used. The nuclear emulsions areinspected using fast automated microscopes recently developed. Acharge assignment efficiency of more than 99% is achieved. Theseparation of Hydrogen, Helium, Lithium, Berillium, Boron and Carboncan be achieved at two standard deviations or considerably more,according to the track length available for the measurement.