Processing apparatus and processing method

A processing apparatus comprising:

• an apparatus main body comprising:
• a base portion that is:
• a movable spindle of a numerical control (NC) machine tool, or
• a movable arm of a multi-axis robot;
• and
• a liquid supply unit that is configured to supply a liquid to the base portion;
• a chuck portion connected to the base portion and including an attachment hole that is open outward;
• a processing tool detachably mounted on the chuck portion and that comprises:
• a cylinder fitted into and held by the attachment hole;
• a drive unit disposed inside the cylinder and comprising a rotating body configured to rotate around a central axis by the liquid introduced from the liquid supply unit via the base portion;
• a rotary shaft protruding outward from an inside of the cylinder along the central axis and configured to rotate integrally with the rotating body;
• and
• a tool portion connected to a tip of the rotary shaft;
• and
• an outer cylinder:
• of which one end is non-rotatably connected to the cylinder,
• that extends along the central axis, and
• that includes an outer cylinder insertion hole into which the rotary shaft is inserted.