Processing apparatus

A processing apparatus comprising:

• a holding table for holding a workpiece;
• a spindle adapted to be rotated;
• a cutting blade mounted on the spindle, the cutting blade having a cutting edge for cutting the workpiece held on the holding table;
• measuring means for measuring an edge projection amount of the cutting edge at a predetermined frequency;
• and
• a data processing unit, wherein
• the data processing unit includes a plurality of functional components including:
• a lower limit recording portion for recording a lower limit of the edge projection amount of the cutting edge as an allowable limit for use of the cutting blade,
• a storing portion for storing blade information including the edge projection amount measured by the measuring means and a cutting distance traveled by the cutting blade at the time of measurement of the edge projection amount, the edge projection amount and the cutting distance being obtained from two or more measurements and being stored in a one-to-one correspondence manner,
• an inclination calculating portion for calculating an inclination indicating a decrease in the edge projection amount with an increase in the cutting distance, from the blade information stored in the storing portion, and
• a predicting portion for calculating a maximum cutting distance corresponding to the lower limit of the edge projection amount from the inclination calculated by the inclination calculating portion.