Abstract: A device for separation of a stack in two distinct parts, including a first part, a second part and a zone of weakness between the first and second parts, and an insertion zone located at the periphery of the stack at or close to the zone of weakness, extending over all or part of the periphery of the stack. The device includes at least one separator capable of penetrating into the insertion zone along a penetration distance until coming into contact with the first part of the stack at at least one first contact point located at the periphery of the stack, and coming into contact with the second part of the stack at at least one second contact point located at the periphery of the stack. The device also includes drive means for making the separator penetrate into the insertion zone as far as the penetration distance and for applying a relative movement between the separator and the stack.