Abstract: A zigzag stacking device includes a stack table, swing roll, oppositely disposed positive and negative electrode unwinders, sealer, and controller. Positive and negative electrode plates and a separator are stacked on the stack table. The swing roll supplies the separator in a zigzag shape to the stack table by horizontal movement. The positive electrode unwinder supplies the positive electrode plate to a folded section of the separator folded in a zigzag shape. The negative electrode unwinder alternately supplies the negative electrode plate to a folded section adjacent to the folded section of the separator to which the positive electrode plate is supplied. The sealer presses and seals the separator when the separator is on the stack table. The controller controls operations of the stack table and sealer to seal the separator whenever the separator is stacked on the positive electrode plate and over the stack table.