Machine tool

A machine tool comprising:

• a motion mechanism unit including a rotary body to be controlled;
• and
• a controller configured to control at least a rotating operation of the rotary body in accordance with a machining program, wherein:
• the controller is configured to:
• check data on an inertia of the rotary body when rotating the rotary body in accordance with the machining program;
• when the data on the inertia of the rotary body has been set, check whether or not a rotation speed of the rotary body specified by the machining program is equal to or lower than a limit rotation speed set according to the inertia of the rotary body;
• and when the rotation speed of the rotary body specified by the machining program exceeds the limit rotation speed, limit the rotation speed of the rotary body specified by the machining program using as an allowable rotation speed a preset rotation speed equal to or lower than the limit rotation speed;
• the controller is further configured to, when the data on the inertia of the rotary body has not been set or when the set data on the inertia of the rotary body is determined to be an abnormal value, limit the rotation speed of the rotary body specified by the machining program to a preset safe rotation speed.