A mounting method includes the steps of, after positioning objects being bonded relative to each other, moving a movable wall positioned there around until coming into contact with one object holding means to form a local chamber having a local enclosed space, enclosing both objects in the chamber, reducing the pressure in the chamber, moving the object holding means in a direction for reducing the volume of the chamber and moving the movable wall following the movement of the object holding means, and bonding both objects to each other by pressing. Since the bonding part and the vicinity of the bonding part can be locally and efficiently enclosed from the surroundings, and the local chamber can vary the shape of the enclosed space with the bonding operation while maintaining the enclosed state even at the time of bonding.