PURPOSE: To guide a sheet properly and smoothly at time of its delivery by moving a conveyor guide in a conveying passage continuing to a movable stretching part by a moving roller of a conveyor belt to be followed to displacement of the moving roller.

CONSTITUTION: A driven roller 88 stretching a conveyor belt 86 receiving an original on platen glass is pivotally supported on a slide plate 751 supported shiftably on a frame 753, and it is kept to tenseness with a spring 752. In this slide plate 751, a bearing 755 fitted in this plate is guided to an L type guide hole 753a of a frame 753, and a guide hole 751a is guided to a pin 755, making it slidable. On the other hand, a V-type guide plate 756 of a return conveying passage 122 fits a long hole 756b of its setting piece 756a in both pins 757, 758 of the frame 753, and follows in displacement of the driven roller 88 with a spring 759, keeping a clearance S in space with the conveyor belt 86 constant. Thus, delivery of a sheet is smoothly performed and a jam or the like can be prevented from occurring.