A device (10) for optically controlling a face (13) of a blank (12) has a vacuum conveyor (20) capable of transporting the blank (12) along a path of travel (15) and which includes a conveyor belt (22) having an apertured structure of which the conveying path follows the path of travel (15) of the blank (12). A suction device (40) is suitable for pressing the blank (12) against the conveyor belt (14). An inspection device (30) inspects the face (13) of the blank (12) during its conveyance by the vacuum conveyor (20). The inspection device is located on the side opposite the vacuum conveyor (20). The suction device (40) delimits three separate successive suction sections (41, 42, 43) along the path of travel (15), including a central suction section (42) that extends opposite the inspection device (30), an upstream suction section (41) and a downstream suction section (43).