To surely remove dust attached to the bottom of a pallet with a workpiece placed thereon and carried into a workpiece processing device.

The pallet cleaning device 401 horizontally conveys the pallet on which the workpiece 103 to be processed is placed and positions the pallet above a processing table 203. A brush body 402 is set outside a space region 204 vertically extended from the processing table 203 and below a bottom face 104 of the pallet 102. The brush body 402 has a rotary shaft 403, and is rotatable around the rotary shaft 403. The rotary shaft 403 is directed toward a direction parallel to the bottom face 104 of the pallet 102 and orthogonal to the conveying direction of the pallet 102. The brush body 402 is rotated in such a manner that the part thereof in contact with the bottom face 104 of the pallet 102 is moved in a direction against the moving direction of the pallet 102.