A three-axial silicon based force sensor with a volume less than 7mm3, developed for biomechanical measurements, has been characterized. Results obtained with two different experimental test benches are reported in this paper. High linearity and low hysteresis during sensor normal loading have been obtained by using a preliminary test bench. A second improved test bench, based on a six-components load cell, has been employed to perform a reliable sensor calibration. A sensitivity matrix has been evaluated from experimental data and an estimation of force accuracy has been determined. The experimental sensitivity in the shear directions is 0.054N−1 and in the normal direction is 0.026N−1. A method for comparing the device characteristics with similar state of the art three-axial force sensors has been provided.