Inside the Fuel Cell, the magnetic field distribution can indicate normal or abnormal operation and therefore provides an effective diagnosis approach. The magneto-tomography is the only noninvasive current density mapping method and is based on the measurement of the external magnetic field of the fuel cell stack. The present work addresses the development of a new magnetic field analyzer device devoted to assess the current density distribution inside the Fuel Cell, within the surrounding external magnetic field. The proposed magnetic field analyzer associates magnetic sensors with a ferro-magnetic circuit, which is essentially different in comparison with other methodologies proposed until now. Providing a higher magnetic field variation at the level of magnetic sensors, this new approach enables a more accurate analysis of the current distribution inside the Fuel Cell. This study considers the Proton Exchange Membrane Fuel Cell case. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.