A machining device can lengthen the lifespan of a tool and improve the machining quality of a workpiece by managing the amount of wear of the tool by machining the workpiece using the other portion of the tool when a portion of the tool is worn and the machining performance of the tool is decreased. The machining device includes: a tool-moving unit coupled to a machining unit to change the position of the tool with respect to the workpiece; a supporting unit supporting the workpiece; a sensor unit disposed at the machining unit and measuring a current amount supplied to a machining motor operating the tool, or an operation force of the tool; and a control unit receiving a measurement signal from the sensor unit and transmitting a control signal to the tool-moving unit and the supporting unit.