The performances of electrical machines highly depend on the behavior of materials, such as steel, copper, and permanent magnet. This paper focuses on permanent magnets whose magnetization must be precisely known. Thus a non-destructive approach which includes a combination of experiments and inverse problem, using the magnetostatic moment method, is presented in order to determine the magnetization of the magnet. With a Hall sensor, a scan of the field around the sample is made. These measurements and a numerical approach allow us to deduce the sample magnetization. Studies of two samples illustrate the advantages of this method.