A device for bonding substrate pairs, with - a first pretreatment module for pretreating a first substrate of a substrate pair with a pretreatment chamber which can be exposed to a vacuum and which surrounds a pretreatment space, with a first lock door, wherein the first pretreatment module for pretreatment of the first substrate of the substrate pair and a second pretreatment module for pretreatment of the second substrate of the substrate pair are provided, - at least one primary treatment module with a primary treatment chamber which can be exposed to a vacuum separately from the pretreatment chamber and which surrounds a primary treatment space, in which the substrate pair can be brought into contact and bonded, while the first pretreatment module can be simultaneously loaded with a further substrate of a substrate pair, - a first primary lock door which connects the pretreatment chamber to the primary treatment chamber vacuum-tight, the first pretreatment module being switchable as a lock for the loading of the primary treatment chamber with substrates, and wherein the first and the second substrate can be loaded into the primary treatment chamber via separate lock doors, - at least one aftertreatment module with an aftertreatment chamber which can be exposed to a vacuum separately from the primary treatment chamber and which surrounds an aftertreatment space, with a second lock door and - a second primary door lock which connects the primary treatment chamber to the aftertreatment chamber vacuum-tight, the aftertreatment module being switchable as a lock for the unloading of the substrates from the primary treatment chamber. - a first pretreatment module for pretreating a first substrate of a substrate pair with a pretreatment chamber which can be exposed to a vacuum and which surrounds a pretreatment space, with a first lock door, wherein the first pretreatment module for pretreatment of the first substrate of the substrate pair and a second pretreatment module for pretreatment of the second substrate of the substrate pair are provided, - at least one primary treatment module with a primary treatment chamber which can be exposed to a vacuum separately from the pretreatment chamber and which surrounds a primary treatment space, in which the substrate pair can be brought into contact and bonded, while the first pretreatment module can be simultaneously loaded with a further substrate of a substrate pair, - a first primary lock door which connects the pretreatment chamber to the primary treatment chamber vacuum-tight, the first pretreatment module being switchable as a lock for the loading of the primary treatment chamber with substrates, and wherein the first and the second substrate can be loaded into the primary treatment chamber via separate lock doors, - at least one aftertreatment module with an aftertreatment chamber which can be exposed to a vacuum separately from the primary treatment chamber and which surrounds an aftertreatment space, with a second lock door and - a second primary door lock which connects the primary treatment chamber to the aftertreatment chamber vacuum-tight, the aftertreatment module being switchable as a lock for the unloading of the substrates from the primary treatment chamber.