To provide a sheet-like material stacking method and a device capable of temporarily treating a plurality of sheets, by correctly stacking the respective sheets in the same position, by smoothly performing work for stacking a flexible sheet-like material such as a plastic foam sheet.

The sheet-like material is placed in a predetermined position without varying its position, by extracting a conveyor from below the sheet-like material by making a driving speed V1 coincide with a moving speed V2, by moving shafts 5A and 5B of a support roller in the inverse direction of the driving direction of the conveyor simultaneously when driving the conveyor, by using the device composed of an endless belt type conveyor 4 supported and driven by a pair of rollers 3A and 3B arranged in parallel and a moving means reciprocating this conveyor itself between a supply means of the stacking sheet-like material 2 and a stacking position.