To surely and uniformly bond substrates by placing a quartz or glass plate on a substrate disk while being dried, and cooling the plate before placed on a next substrate disk after the drying process in which heating is carried out.

A bonded substrate disk 23 is taken out of a bonding station 10, placed on a different circular switch table 25 of a drying station 26, periodically guided to below a UV drier 27 and dried in the drying station 26. A quartz or glass plate 29 is paced by a glass plate-operating apparatus 28 on the substrate disk 23 to be dried. The quartz or glass plate is positioned on the substrate disk 23 by its own weight. The glass plate 29 is cooled by an ionized air after taken out from the substrate disk 23 by the glass plate-operating apparatus 28, and then placed on a different substrate disk 23 again. The dried substrate disk 23 is taken out from the circular switch table 25 by an operating apparatus 30 and supplied to a receive station 31.