Abstract: A device for turning over book leaves is disclosed, which comprises a book holder for supporting a book in an open state, a movable unit disposed above the book holder and capable of vertical and horizontal movement, and a turn-over roller and a pinch member both mounted in said movable unit. The turn-over roller is brought into contact with the page of the book to be turned over with the movement of the movable unit. Then it is rotated toward the book seam to cause a plurality of book leaves including a leaf to be turned over to be turned up in between it and the pinch member. Then it is rotated in the opposite direction to release the turned-up leaves other than the leaf to be turned over. The remaining leaf to be turned over is moved with the movement of the movable unit toward the book seam to effect the turn-over.