摘要： According to recent studies on electrical insulation systems, the nanocomposite organic/inorganic hybrid materials (NC) assure a distinct improvement of their high-temperature functioning and allow strengthening the dielectric properties of these systems. Recently it was shown that some modifications of the electrical properties such as the permittivity, dielectric breakdown and materials lifetime, were often awarded to the properties of what it is called the interphase. This interphase represents the interaction zone between the nanoparticles and the matrix and plays very often a leading part in the definition of the macroscopic properties. In this paper, Atomic Force Microscopy (AFM) is used to make, at the same time, qualitative and quantitative measurements of these interaction zones. For example, Peak Force Quantitative Nano Mechanical (PF QNM) mode, would allow to highlight the presence of the interphase by measuring mechanical properties (Young’s modulus, deformation and adhesion). As a result, this new and original study on Polyimide/Silicon Nitride (PI/Si3N4) nanocomposite confront experimental results with theoretical models.