Machine tool having calibration device for calibrating centering sensor

The invention relates to a machine tool for machining pre-toothed workpieces, comprising a workpiece holder (20) and a workpiece spindle (21), which has a workpiece spindle housing (211) and a workpiece spindle central shaft (212) that can be rotated about a workpiece spindle axis (A). The machine tool further comprises: a centering sensor (1) which is designed to determine the phase of the teeth of the workpiece (23) rotating about the workpiece spindle axis (A); a calibration member (10) located at a defined calibration position (CM) relative to the workpiece spindle (21); and a sensor controller which is designed to carry out the following methods: moving the centering sensor (1) relative to the workpiece spindle (21) into a calibration position, in which the centering sensor (1) is located on the calibration element (10); determining a response performance of the centering sensor (1) in that the sensor controller (3) moves the centering sensor (1) relative to the calibration element (10) and receives a se