To provide a drilling method in which a machining program need not be prepared in advance even when the centers of a plurality of pads of a work cannot be specified in advance, and the operation efficiency and the product reliability can be enhanced.

The image of a surface of a work 1 placed on a Y-table 16 is picked up by a line camera 51 prior to machining. The center position of each pad is specified from the obtained image pickup data, and a machining program is generated based on the specified center position. A hole is machined in the center of each pad according to the generated machining program.