To enable easy and rapid conveyance of a plurality of items to be piled up without collapse of loads and automatically conducting a series of operations from an operation of plastering a tack label to the item to be piled up through an operation of piling up the item to be piled up with the plastered label to an operation of conveying the items to be piled up.

A load collapse preventing structure is obtained by piling up a plurality of items to be piled up each via a nonslip means wherein the nonslip means is a tack label and the tack label comprises a display portion plastered on a side surface of the item to be piled up to give a predetermined display and a nonslip portion having a nonslip layer plastered on the side surface of the items to be piled up and possessing the nonslip property between the upper surface of the item to be piled up and the lower surface of the item to be piled up in the upper step both being integrally arranged.