To provide a machining device predicting the crack of a wafer before dicing the wafer.

The machining device is provided with a machining means including: a machining tool grinding or polishing a wafer held on a chuck table; a spindle to which the machining tool is attached; a motor driving the spindle; and a power supply means supplying power to the motor. The machining device includes: a load current value detection means connected to the motor and the power supply means in series and detecting a load current value of the motor; a storage means storing a normal load current value normally generated in the machining of a wafer; an abnormality detection means detecting the abnormality of a load current value by comparing a load current value detected by the load current value detection means with a normal load current value stored in the storage means; and a recording means recording the abnormality of a load current value detected by the load current value detection means and a load current value detected by the abnormality detection means.