A sheet feeder has a suction head 11 arranged above a sheet pile 8 placed on a lifting table 7, with suckers 19 thereon movable between raised starting and lowered gripping positions. Each sucker 19 has a respective sensor 20 to detect the level of the sheet pile 8 below, and an adjustment device 16 to adjust the starting position. The height of the head 11 is also adjusted depending on its position detected by sensor 14. The table itself can be raised depending on the sensed level of the front of the pile.
