PURPOSE: To prevent deformation, bent of a conveyor due to a load by providing a protrusion having the same height as that of an engaging protrusion on the lower surface of the conveyor in a conveying apparatus in which the protrusion of the conveyor of an upper layer is engaged with the connecting step of the conveyor of a lower layer.

CONSTITUTION: A plurality of protrusions 6 having the same height as that of an engaging protrusion 4 are provided in the recesses 5 of the lower surface of a conveyor 1. When the conveyor 1 is mounted, the protrusions 6 of the conveyor 1 of an upper layer are so deviated as not to be brought into contact with a wall forming a recesses 2 in the lower layer conveyor 1 but to be brought into contact with the bottom walls of the recesses 2. Accordingly, even if heat or load of long time is applied to the center of the conveyor 1, it prevents the deformation, bent of the protrusion 6 due to contact with a placing surface A.