Hole drilling process, and drilling tool

A hole drilling process for drilling a hole on a supported member to be processed by using a first drilling tool that can drill a hole with a diameter smaller than that of a target hole, and a second drilling tool that can drill a hole with a diameter equal to the diameter of the target hole, the process comprising:

• a temporary hole drilling step in which a temporary hole with a predetermined depth set beforehand is drilled by moving the first drilling tool to a drilled position set beforehand;
• a hole measuring step in which a distance between an existing target hole and the temporary hole;
• a drilled position correcting step in which the drilled position is corrected based upon the distance between the existing target hole and the temporary hole;
• and
• a target hole drilling step in which the target hole is drilled by moving the second drilling tool to the corrected drilled position.