Elastic properties of nanostructures are crucial for the adequate design and long term use of nano/micro-electro-mechanical system (NEMS/MEMS) as well as their utility in nanoindentation. Carbon nanostructures were fabricated by focused ion beam (FIB) assisted deposition and milling using Naphthalene (C10H8) as a precursor gas. Cantilevers of size 3-10 µm were fabricated and their elastic properties were monitored. An end point load was applied by successive deposition of Pt or carbon in a form of vertical column. Euler–Bernoulli beam theory was applied to examine the mechanical properties of the cantilever. It has been observed that expected deflection of the carbon nano-cantilever is significantly different compared to most of the reported micro or nano-sized carbon or diamond structures. Initial investigation of such a discrepancy suggests that Ga implantation and presence of core-shell type structure are the main causes of altered mechanical properties.