Atomic force microscopy has been used to investigate the mechanical properties of microtubules. Method of Salvetat et al. , originally developed for measuring the Young's modulus of carbon nanotubes, has been extended to a biological system of similar geometry. Preliminary measurements of Young's modulus of microtubules in this configuration give a value of 74 MPa. Compression measurements on the same system give a value of 22 MPa, which is of the same order of magnitude, while values previously reported in the literature have a dispersion of 3 orders in magnitude, from 1MPa to 1GPa. Further improvements of our method will enable comparison between the properties of different types of microtubules, for example, between those from healthy and diseased tissue.