In this paper, we analyze the mechanism of the phenomenon between an endeffector, a micro object and a substrate during a micro manipulation. In a micro range, the attracting forces such as the van der Waals, capillary, and electrostatic forces dominate and course adhesion between the object and the endeffector. The adhesion makes the manipulation of an object difficult. Recently, we developed a method to reduce the attracting/adhesion effect. When bringing an oscillating endeffector close to a micro object on a substrate, the attracting force between the object and the endeffector is reduced, attracting the object to the substrate. Then, it becomes easy to remove the endeffector from the object. Using this method, a micro object can be easily manipulated. However, the mechanism of the phenomenon is still unclear. In this paper, we develop the theoretical model of the system to analyze the phenomenon, and simulate the dynamical motion of the system. Comparing the experimental results, we show the validity of our approach. Using simulation and experiment, we show that the oscillation of the endeffector can reduce the adhesion effect between the endeffector and the object, attracting the object to the substrate. © 2006 IEEE.