An assembly includes: a pair of glass substrates; a peripheral wall disposed between the glass substrates; partitions; an evacuation port; and air passages. The partitions are provided to partition an internal space, surrounded with the glass substrates and the peripheral wall, into an evacuation space and a ventilation space. The evacuation port connects the ventilation space to an external environment. The air passages are used to evacuate the evacuation space through the evacuation port. The air passages include particular air passages arranged in a second direction perpendicular to a first direction, in which the glass substrates face each other, to constitute a ventilation path running through the internal space in the second direction.