A gear cutting machine (1) for which a machining tool (30) detachably attached to a tool spindle is changed by means of an automatic tool changing device, wherein the automatic tool changing device is provided with: a tool holding means (90) for detachably holding a replacement machining tool (30); a moving means (70, 80) for moving the tool holding means (90) in a direction parallel to the axial direction of the tool spindle; and a rotating means (83, 91) for rotating the tool holding means (90).
