Method for changing stack composed of pages

The invention relates to a method for changing a stack composed of pages in a feeder of a page treatment machine, wherein the pages are divided and treated in a lifted auxiliary stack so that a main stack which is arranged on a bracket moves to a position below the auxiliary stack in the feeder along a horizontal conveying road section so that the main stack is lifted and combined with the auxiliary stack for obtaining a new main stack. The pages are divided from the new main stack and treated. The position of the main stack relative to the brackt is determined when a first measurement point outside the feeder in the conveying road section is in a static state or moving state of the bracket, or is determined when a second measurement point in the feeder in the conveying road section is inthe moving state of the bracket. The main stack is driven by a driver and moves to a position below the auxiliary stack in the feeder so that the main stack is coaxially arranged to the auxilary stackbefore lifting. According