The paper deals with the testing of a rotary head for ultrasonically aided electrical discharge machining (EDM+US) that can be used at finishing and semifinishing modes and EDM with complex kinematics - “milling EDM”. The rotation movement using of the electrode-tool is justified by the fact that during the EDM process, the energy is dissipated over the machined surface, and thus its roughness is decreased. But this comes also with the higher instability of EDM process, often short-circuits between the tool and the workpiece, and the idle state due to the variable gap. The tool ultrasonic vibrations oriented perpendicular on the frontal machined surface confirmed both roughness and EDM stability improving, and consequently machining rate, at all working modes tested in this research. The curves of roughness and machining rate are presented at different values of tool rotation speed and consumed power on ultrasonic chain. The obtained surface microgeometry was also studied using scanning electron microscope.