A digital holographic characterization of Bessel beams produced by polymeric microaxicons is reported. Both intensity and phase of the beam can be numerically reconstructed in whichever point starting from a single acquired hologram. Optical parameters such as the full width at half maximum, the focal length and the depth of focus of the axicon lens are experimentally measured. The Bessel beam exiting from the axicon, with a very large depth of focus with respect to that of a Gaussian beam, is successfully exploited for optical trapping of micrometric objects.