To decrease inferiority of mounting of a minute ball in a workpiece, by improving efficiency and accuracy in mounting the minute ball on the workpiece.

This device is provided with a sucker head 31, providing a sucker jig 33 formed with a plurality of sucker holes in an upper surface side to attract a fine ball to the sucker hole of the sucker jig 33 by a second sucker device 34, and a ball mounting mechanism 14 having a head clamp mechanism 65 clamping the sucker head 31 also inverting the clamped sucker head 31 to make the sucker jig 33 of the inverted sucker head 31 approach to a workpiece W by moving the head clamp mechanism 65 upward of the workpiece W lowered down. In the case of approaching of the sucker jig 33 to the workepiece W by the ball mounting mechanism 14, sucking by the second sucker device 34 is released, and a fine ball B is mounted in the workpice W.