Machine tool

A machine tool comprising:

• a casing and a movable cover that define a machining region in which a workpiece is machined;
• a rail;
• a drive portion that moves the movable cover on the rail;
• cleaning means that removes a foreign object on the rail;
• a body control unit that controls the drive portion so as to move the movable cover on the rail;
• and
• detection means that detects a foreign object on the rail,
• wherein the body control unit performs
• step ST01 of transmitting, to the drive portion, an open/close command for moving the movable cover to be opened or closed;
• step ST02 of determining, after the step ST01, whether or not a foreign object is present on the rail using the detection means;
• step ST03 of controlling the drive portion so as to move the movable cover to be opened or closed, if it is determined in the step ST02 that no foreign object is present on the rail;
• and
• step ST04 of removing, if it is determined in the step ST02 that a foreign object is present on the rail, the foreign object on the rail using the cleaning means, and thereafter returning to the step ST02.