A processing apparatus includes a processing unit, a control unit, and a temperature detecting unit. The processing unit includes a cutting blade and a spindle assembly, the spindle assembly including a spindle having the cutting blade mounted on a distal end of the spindle and a spindle housing through which the spindle is inserted. A cooling fluid passage is formed in the spindle housing, the cooling fluid passage cooling the spindle assembly, and having one end connected to a cooling fluid supply source and having another end communicating with a cooling fluid outlet of the spindle housing. The temperature detecting unit detects the temperature of the spindle housing. The control unit determines whether a state of cooling of the spindle assembly is normal or abnormal on the basis of the temperature detected by the temperature detecting unit.