PURPOSE: To carry out suction conveyance corresponding to the size of a sheet type body by suckingly driving a suction conveyance means in a condition corresponding to the size of a detected sheet type body in accordance with the output of a detecting means and starting conveyance after sucking the sheet type body.

CONSTITUTION: The size of originals 1 which are stackedly housed in a housing means 77 is detected by an original size detector. Then, a defined value corresponding to the time it takes for the original 1 to be surely sucked to the outer peripheral face of the belt 84 of a suction conveyance means 38 in accordance with the size of the original 1 is inputted as the set value of a timer. Thereby, the original 1 is conveyed after being surely sucked, preventing skewing caused by starting paper feeding in an insufficiently sucking condition, the clogging and further the breakage of the original caused by the shifting in the sucking position of the original with respect to the belt 84, and the like.