Optical beam deflectors are used to control direction of the optical beam therefore accuracy of the optical system strongly depends on dynamic characteristic of the deflector. Three degrees of freedom (3DOF) piezoelectric micro-actuator for optical beam deflector is investigated in the paper. Piezoelectric micro-actuator consists of piezoelectric cylinder and ferromagnetic hemisphere that contacts the cylinder in the three points. Electrodes of the outer surface of the cylinder are divided into three sections. Three harmonic electric signals are used for piezoelectric cylinder excitation. Numerical and experimental study was performed to analyse dynamic characteristics of the piezoelectric actuator. Results of the studies are compared and discussed
