CUTTING DEVICE, SENSOR UNIT, AND DETECTION METHOD

Provided is a cutting device with which it is possible to precisely and easily detect rattling of a blade. The cutting device has: a table on which an object is placed; a cutting part having a blade for cutting the object, and a rotation drive part for causing the blade to rotate; and a first photoelectric detection part for detecting the position of an edge portion of the blade, the first photoelectric detection part having a Z-axis movement mechanism for causing the table or the cutting part to move in a Z-axis direction in which the distance between a placement surface and a rotational axischanges, an X-axis movement mechanism for causing the table or the cutting part to move in an X-axis direction, a first emission part for emitting light, and a first incidence part disposed so as tosandwich the edge portion of the blade together with the first emission part, the light emitted by the first emission part being incident on the first incidence part. A first detection axis connectingthe first emission part an