PLATE WORKING AND CHECKING METHOD

PURPOSE:To fix a plate stably during working or checking by sticking a film sheet to one side surface of the plate, and making the film sheet subject to air suction. CONSTITUTION:When a substrate 1 is locked on a working table 11, a film sheet 2 is stuck to a setting surface of the substrate 1, and the backside of this film sheet 2 is mounted on top of a vacuum chuck 18 and attracted by suction force. With this air suction, a through hole 3 of the substrate 1 is closed by the film sheet 2, so that suction force of the vacuum chuck 18 will in no case go down at all, and in addition, the film sheet 2 is not situated on a working surface 4 of the substrate 1, through which it is not broken by the working, whereby the substrate 1 can be surely locked in a stable manner during operation. Moreover, since the film sheet 2 is bonded over the whole setting surface of the substrate 1, there is no effect on flatness or the like of a surface of the substrate 1, thus highly accurate working can be done in this way.