The invention relates to an ultrasonic actuator, preferably for use in an ultrasonic motor, in the form of a piezoelectric plate with a length L, height H and thickness t, wherein the piezoelectric plate has a lateral plane of symmetry Sq, a longitudinal plane of symmetry Sl and at least two main surfaces, and the piezoelectric plate comprises at least two generators symmetrically disposed with respect to plane of symmetry Sq for generating ultrasonic standing waves. According to the invention, the piezoelectric plate has a shape that includes at least eight lateral surfaces, wherein at least two of the lateral surfaces are working surfaces for contacting of elements to be driven, and at least two of the lateral surfaces are holding surfaces for holding the piezoelectric plate, and the remaining lateral surfaces are free surfaces, wherein at least four free surfaces are arranged at an identical angle α with respect to the longitudinal plane of symmetry Sl and/or at an identical angle φ with respect to the lateral plane of symmetry Sq.