A plurality of suction holes are formed in a conveyance belt of a conveyor device. A suction unit is arranged on one of surfaces of the conveyance belt. The suction unit includes a unit case in which cells adjacent in a paper conveyance direction are formed and defined by a partition wall extending in a width direction of the conveyance belt, a ceiling wall interposed between the unit case and the conveyance belt, and a fan provided in each of the adjacent cells. The ceiling wall includes a slit group which communicates the respective adjacent cells with the plurality of suction holes. The slit group includes a plurality of slits formed across the partition wall. The plurality of slits formed across the partition wall include slits in communication with one of the adjacent cells and slits in communication with the other of the adjacent cells.