A centering device for a plate-shaped workpiece comprises: a table (21) having a conveyor mechanism (23) for conveying a plate-shaped workpiece (10) in the horizontal direction; a camera (56) for taking an image of the plate-shaped workpiece (10) placed on the table (21); a table movement mechanism (28) for moving the table (21) horizontally in the direction orthogonal to the conveyance direction; a table rotation mechanism (60) for rotating the table (21) about a vertical axis; a computation unit (58) for comparing target central position information and information acquired by the camera (56) and computing the movement amount of the conveyor mechanism (23), the movement amount of the table movement mechanism (28), and the movement amount of the table rotation mechanism (60); and a control unit (59) for controlling the conveyor mechanism (23), the table movement mechanism (28), and the table rotation mechanism (60) on the basis of the movement amounts calculated by the computation unit (58).