Abstract: The collating stacker comprises a hopper mounted for oscillation between first and second positions at right angles to each other. Individual microfiche are fed into the top of the hopper so that the microfiche can be received and stacked in the hopper to form a first set when the hopper is in the first position and a second set after the hopper has been rotated to its second position at right angles to the first position. By this arrangement, the first and second sets can be easily manually separated as they are removed from the hopper.