PURPOSE: To efficiently produce a liquid crystal display element having different substrate dimension by moving both of the part for regulating the moving direction and the part for pushing the material to be treated on a carrier mechanism and providing a function capable of treating the material to be treated which is different in width by the same device.

CONSTITUTION: A roller holding fitting 6 is moved to the position of a roller holding fitting 7 by actuating a driving system. Further, a slide fitting 21 connected to the fitting 6 is moved by this movement. Therefore, the position of a slide roller 20 is moved via a bearing according to movement of the slide fitting 21. As a result, the position of a rubber ring 17 brought into contact with a glass base plate 1 is moved to the end part of the glass base plate 1 and the carrier width is changed. In such a way, e.g. the glass base plate is treated in the different carrier width by interlocking the movement of a riding roller 16 with the movement of a mechanism for changing the carrier width.