This PhD aims to develop analytical techniques enabling to access information on both atomic structure and polarization in two-dimensional van der Waals (2D vdW) ferroelectronic materials. Recently, 2D vdW ferroelectric systems have been discovered with novel polarization mechanisms explained by subtly tuned atomic structural configurations. To understand the mechanisms that drive spontaneous polarization, the ability to probe atomic position and induced properties in atomically thin 2D layers is essential but still a big challenge. Thanks to improvements in detector efficiency and new numerical data treatment capability, transmission electron microscopy (TEM) is becoming an invaluable tool for the study of 2D materials. Aberration correctors allow low voltage operation to avoid damage and provide direct atomic structure, and EELS can provide chemical composition at the atomic level. More recently, 4D-STEM can be used to determine the local electric fields and charges generated in atomically thin 2D materials with sub-angstrom accuracy. The PhD project will use all these new developments recently realized in MEM-LEMMA to explore the feasibility of accessing information on local polarization in innovative 2D vdW ferroelectric materials developed by the collaborators; SPINTEC (CEA) and NCSR (Greece).