Conductive balls are transferred from a pallet onto an array of conductive pads on a semiconductor chip by means of a transfer apparatus; the transfer apparatus includes a pallet formed with an array of recesses same in pattern as the array of conductive pads, a movable head formed with an array of vacuum holes and a driving mechanism for moving the head from an idle position onto the pallet and from the pallet to the semiconductor chip; when the head is moved to the pallet, the vacuum holes are connected to the recesses so as to confine the conductive balls in the narrow spaces; the vacuum is developed; then the conductive balls are traveled through the closed spaces to the vacuum holes; even if the conductive balls have been charged, the conductive balls are never attracted to the adjacent balls, and are surely captured by the vacuum holes.