Abstract: A board stage of an aligner that can avoid bending of a printed circuit board to be exposed and accomplish high accurate exposure. In one preferred modes a suction plate 2 having small holes 20 is mounted on a supporting body on which a space 30 bigger than the small holes is provided. The holes 20 are connected to the space 30 and to a vacuum device via an air passage 31 and a bottom passage 32. The diameter of the suction hole 20 is so less than 0.4 mm not to make at the printed circuit board such bending that causes exposure troubles.