A method for manufacturing an organic EL device, in which constituent layers of an organic EL element are formed over a substrate in the form of a strip by deposition, while the substrate is being moved in the longitudinal direction, the method comprising: a constituent layer-forming step of performing deposition over one surface of the substrate, while the substrate is being moved in the longitudinal direction, sequentially in at least an upward deposition unit and a lateral deposition unit arranged along the moving direction of the substrate by discharging a vaporized material from an evaporation source, the constituent layer-forming step comprising: an upward deposition step of performing deposition over a deposition surface of the substrate, while the substrate is being moved with its deposition surface facing downward, in the upward deposition unit by discharging the vaporized material from the evaporation source arranged below the substrate toward the deposition surface; a lateral deposition step of performing deposition over a deposition surface of the substrate, while the substrate is being moved with its deposition surface facing laterally, in the lateral deposition unit by discharging the vaporized material from the evaporation source arranged laterally of the substrate toward the deposition surface; and a direction changing step of turning the substrate conveyed from the upward deposition unit so as to change the facing direction of the deposition surface from downward to lateral, by means of a guide mechanism provided between the upward deposition unit and the lateral deposition unit, while supporting the substrate from the non-deposition surface side so that the non-deposition surface of the substrate faces the inside of the turn, so as to guide the substrate to the lateral deposition unit. a constituent layer-forming step of performing deposition over one surface of the substrate, while the substrate is being moved in the longitudinal direction, sequentially in at least an upward deposition unit and a lateral deposition unit arranged along the moving direction of the substrate by discharging a vaporized material from an evaporation source, the constituent layer-forming step comprising: an upward deposition step of performing deposition over a deposition surface of the substrate, while the substrate is being moved with its deposition surface facing downward, in the upward deposition unit by discharging the vaporized material from the evaporation source arranged below the substrate toward the deposition surface; a lateral deposition step of performing deposition over a deposition surface of the substrate, while the substrate is being moved with its deposition surface facing laterally, in the lateral deposition unit by discharging the vaporized material from the evaporation source arranged laterally of the substrate toward the deposition surface; and a direction changing step of turning the substrate conveyed from the upward deposition unit so as to change the facing direction of the deposition surface from downward to lateral, by means of a guide mechanism provided between the upward deposition unit and the lateral deposition unit, while supporting the substrate from the non-deposition surface side so that the non-deposition surface of the substrate faces the inside of the turn, so as to guide the substrate to the lateral deposition unit. an upward deposition step of performing deposition over a deposition surface of the substrate, while the substrate is being moved with its deposition surface facing downward, in the upward deposition unit by discharging the vaporized material from the evaporation source arranged below the substrate toward the deposition surface; a lateral deposition step of performing deposition over a deposition surface of the substrate, while the substrate is being moved with its deposition surface facing laterally, in the lateral deposition unit by discharging the vaporized material from the evaporation source arranged laterally of the substrate toward the deposition surface; and a direction changing step of turning the substrate conveyed from the upward deposition unit so as to change the facing direction of the deposition surface from downward to lateral, by means of a guide mechanism provided between the upward deposition unit and the lateral deposition unit, while supporting the substrate from the non-deposition surface side so that the non-deposition surface of the substrate faces the inside of the turn, so as to guide the substrate to the lateral deposition unit.