A buffer device for temporary storage and flow control in a product conveying system includes a plurality of vertically movable product holders at an inlet end and outlet end, and an elevator system for placing product holders in a conveying plane of the conveying system and vertically moving the product holders. The elevator system preferably includes a chain loop at the inlet end and a chain loop at the outlet end, both of which are equipped all around with product holders, and the chain loops can move in opposite directions.