A sheet-shaped electrode conveyance device (A) for conveying the sheet-shaped electrodes (1) to the stacking station is covered by the sealing walls (50). The inside of the sealing walls (50) is divided along the conveyance route of the sheet-shaped electrode (1) by the partitions (57, 58, 59, and 60) into the inside space regions (Z1, Z2, Z3, Z4, and Z5). Dry air is supplied to the inside space regions (Z1, Z2, Z3, Z4, Z5). If there is an abnormal sheet-shaped electrode (1) inside any of the inside space regions (Z1, Z2, Z3, Z4, Z5), the conveyor plates (20) other than the conveyor plate (20) carrying the abnormal sheet-shaped electrode (1) are retracted to the inside space regions other than the inside space region where the abnormal sheet-shaped electrode (1) is present.