We have a probe station dedicated to the characterization of Microsystems and Microelectromechanical systems in order to study the properties of micro-actuators and micro-sensors. The measured performance of these actuators are based on electrostatic effects, thermal effects and piezoelectric effects. A set-up which uses I/V amplifiers together with synchronized detection allows the treatment of signals from differential capactive micro-sensors and permits access to nanometric precision movement. Another important part of the characterization concerns the measurement of electromechanical micro-resonators working from KHz to GHz using synchronized detection at 2 M, an impedance meter (to 110 MHz) and network analyzers. In terms of the characterization of RF micro switches, the electromechanical characterization of the actuation part of the switch is coupled to the high frequency characterization due to the expertise mention above.