Machine tool and display control device

A machine tool comprising:

• an attachment portion to which a tool is attachable;
• a memory storing various programs and set data;
• and
• a processor including an input unit, a numerical control unit, a vibration detection unit, and a display control unit,
• wherein the input unit receives input of an operation of an operator;
• the numerical control unit controls movement of the attachment portion and a rotating speed of the tool in accordance with a machining program;
• a vibration detection unit detects vibration of the tool;
• and
• a display control unit controls display of time-series data indicating a change in a vibration level detected by the vibration detection unit and a change in the rotating speed of the tool,
• wherein upon receiving an instruction to change the rotating speed from the input unit, the display control unit displays a marker indicating a timing of the change instruction so that the marker is superimposed on the time-series data.