Abstract: A method of transferring conductive balls via a suction head without picking up errors and mounting errors includes moving a suction head with pores towards the conductive balls located in a case and applying a vacuum pressure to the pores to suck and pick up the conductive balls. While the suction head is moved away from the case, the suction head is vibrated by oscillators at different frequencies changed within a predetermined frequency range, thereby dropping redundant conductive balls from the suction head. Further, the suction head is moved to a position above a work piece and moved towards the work piece. The pores are communicated with atmosphere to mount the conductive balls onto the work piece. While the suction head is away from the work piece, the suction head is vibrated by oscillators at different frequencies changed within a predetermined frequency range.