The product flow regulator is used for decoupling an incoming flow of piece-goods from a downstream device for further processing. It comprises a stationary intermediate storage with a plurality of store levels, an infeed-side elevator with one or more transport levels for taking products arriving on conveyors to intermediate storage and a discharge-side elevator for removing the temporarily stored products and delivering them to forwarding conveyors. A buffer device is arranged upstream from these elevators on the infeed side and downstream from these elevators on the discharge side.