Suction pad having a patterned attracting surface

摘要

A skirt section has a plurality of substantially elliptic projections and a recessed portion formed on an attracting surface thereof. The skirt section is separated from each other by predetermined spacing distances along a circumferential direction of the skirt section on concentric circles. The recessed portion enables a fluid under the negative pressure to be supplied to the entire attracting surface except for the projections. Even if oil film or water droplet adheres to an attracted surface of a workpiece, the workpiece can reliably be attracted without causing a slip.