Cutting machining device

A cutting machining device comprising:

• a head to which one first tool is fixed;
• a holding unit that is disposed to face the head and holds a workpiece;
• and
• a controller that controls a movement of the head and the holding unit, wherein
• the holding unit includes
• a workpiece holding portion that holds the workpiece,
• a contact plug that a tip portion of the first tool fixed to the head is contactable,
• a cover having a box shape, including a surrounding wall to which the workpiece holding portion is fixed, and having a first opening in which the contact plug is detachably held in a position separated from a fixed section to which the workpiece holding portion in the surrounding wall is fixed, and
• a touch sensor that detects contact of a tip portion of the first tool with the contact plug, and
• the controller includes a calculator that calculates a machining start position when cutting machining is performed on the workpiece by the first tool, based on a preset initial position of the head and a contact position of the head, which is detected by using the touch sensor, when the tip portion of the first tool comes into contact with the contact plug.