Patent ID: 7952050

Claim:
A drilling method comprising the steps of: measuring heights of a surface of a table on which a workpiece is to be mounted, from a predetermined reference surface, at lattice points before mounting the workpiece thereon, and storing the measured heights of the surface of the table at the lattice points; measuring height at a desired point of a top surface of the workpiece, mounted on the table and having a uniform plate thickness, before machining; obtaining the height of the surface of the table at the desired point by an arithmetic operation using the heights of the surface of the table at four lattice points of a minimum unit surrounding the desired point; setting the difference between the measured height of the top surface of the workpiece at the point, and the height of the surface of the table obtained by the arithmetic operation, as the plate thickness of the workpiece; setting the height of the top surface of the workpiece at another machining position as the heights with the plate thickness added to the heights of the surface of the table at the machining position obtained by the arithmetic operation using the heights of the surface of the table at four minimum lattice points surrounding the other machining position; and drilling the other machining position.