PURPOSE: To automatize linkage to following processes by providing a device which swings a pair of plate absorbing devices simultaneously, and superimposing a positive plate and a negative plate alternately in a holder so as to form a plate group.

CONSTITUTION: One plate absorbing device 9 takes a negative plate 3, which is stored in a holder 6 provided on the first conveyor 7, out of a holder 11, then is rotated by 90° by means of a swing device 10 so as to insert the negative plate 3 into a holder 11 on a third conveyor 12. Simultaneously, the other plate absorbing device 9' attached to the swig device 10 absorbs a positive plate 2 which is stored in a holder 6' on a second conveyor 7', then is turned by the swing device 10 by 90° in the opposite direction so as to insert the positive plate 2 into the holder 11. This movement is repeated for preset times so as to constitute a plate group 4 of required sheets. Thus, the plate group is alined in the holder 11 so that a manufacturing device for plate of excellent operational efficiency and full automation can be obtained.