The industrial interest for vegetal bast fibers used as composite materials reinforcements increases. This tendency is explained by their low impact on the environment and their very interesting specific mechanical properties [1] which make them attractive for transported applications. The tensile properties of the elementary fibers are well described in the literature [2], but additional information at the cell wall scale is needed to better understand the relationship between their ultrastructure and their mechanical performance. The aim of this work is to present first results from manipulations performed in atomic force microscopy (AFM) associated with PeakForce Quantitative Nanomecanique (PF-QNM) mode.