Machine tool

1. A machine tool that removal-machines a workpiece by means of a tool, comprising:

a workpiece spindle device that holds the workpiece;

a tool spindle device that holds the tool that removal-machines the workpiece;

a robot provided in a machining chamber; and

a cleaning mechanism that is disposed inside a recess defined in a side of the machining chamber and cleans the robot by removing an adhering substance which adheres to the robot, the recess being sized such that at least a part of the robot enters the recess, wherein

when the robot is cleaned, at least a part of the robot moves relative to the cleaning mechanism and enters the recess, and

the cleaning mechanism cleans the at least a part of the robot that is located in the recess.

2. The machine tool according to claim 1 , wherein

the cleaning mechanism is fixedly placed in the machining chamber,

the robot can move and change its orientation in the machining chamber, and

when the robot is cleaned, the robot moves and changes the orientation to change a location of the robot to be cleaned by the cleaning mechanism.

3. The machine tool according to claim 1 , wherein

the cleaning mechanism ejects fluid with respect to the robot, to remove the adhering substance.

4. The machine tool according to claim 1 , wherein

the cleaning mechanism contacts at least one of the robot and the adhering substance, to remove the adhering substance.

5. The machine tool according to claim 1 , wherein

the cleaning mechanism cuts and fractionates the adhering substance.

6. The machine tool according to claim 1 , further comprising:

a cover which covers an inside of the machining chamber.