Abstract: Automatic process line for exposing photosensitive printing plates with a film and a mask, if any, lying thereon, in a light box. Magazines (13, 14, 15) for plate, film and mask are disposed one above the other in said order from top downwards, displaced in stepped relationship to each other at one side thereof with the lowermost magazine projecting furthest. Moreover, means (20) are provided for picking up plate, film and mask separately at said one side and for picking up the plate also at the opposite side and for displacement thereof stepwise from the pick-up position to a deposit position at said one side of the magazines as well as disposition of plate, film and mask in registered position one on top of the other. A transfer member (33) is provided for receiving plate, film and mask in the deposit position and transferring them to a light box (42) with plate, film and mask in exposure position.