To provide a method adopting an extremely easy and effective solution and a device for executing the method by inserting a marker prearranged for dividing a single stack mounted on a pallet into two continuous reams and dividing them into reams.

A projecting part of a marker is bent upward and a pressure element is pressed against the front surface of a stack form thereon to raise it using the frictional properties of the pressure element attaching reams 5 which are already divided by markers 2, to the end of an arm 8 connected to an actuator 9 and capable of movement in a direction angled upwardly and toward the front face of the stack P so that the reams 5 are divided from a stack P.