A chain-driving mechanism and a conveyor apparatus of the present invention include a plurality of rollers (20) arranged to convey to-be-conveyed objects, a driving mechanism that drives the rollers (20) in conjunction with each other, and a motor (80) that exerts a driving force onto the driving mechanism. The driving mechanism includes a plurality of sprockets (40) that rotate coaxially with and together with the rollers (20), an endless chain (50) wound onto the sprockets (40), and a chain guide (60, 61, 62) disposed adjacent to the chain (50) so as to sandwich the chain (50) from the outside in the upward and downward directions. With this structure, there is no need to adjust the stretch of the chain, and the chain can be prevented from slipping off. Additionally, the structure can be made simpler, and costs can be made smaller.