To provide a cutting device having a structure in which an adjustment width such as an air angle and a height or the like is large and which can blow off a cutting fluid by strongly blowing air.

An external air jetting mechanism includes an adjustment means for adjusting a direction and a height of an air jetting nozzle. Air is jetted before a shutter opens an opening to approximately remove a cutting fluid on a workpiece in advance. Accordingly, a water droplet of the cutting fluid is prevented from being scattered by an air jet of an internal air jetting mechanism which is jetted after the opening is opened, and prevented from adhering to an objective lens of a microscope through the opening.