A flow battery includes a cell, a bipolar plate which is in contact with one of a positive electrode and a negative electrode constituting the cell, a current collector plate which has a terminal portion that is led out to the outside of the cell and is electrically connected to the bipolar plate, and a supply/discharge plate which is stacked on the current collector plate and supplies and discharges electrolytes to and from the cell. When the side of the supply/discharge plate facing the current collector plate is regarded as a front surface and the side opposite thereto is regarded as a back surface, the supply/discharge plate has an insertion hole which passes between the front surface and the back surface thereof and into which the terminal portion is inserted, and the terminal portion passes through the insertion hole and extends from the front surface side to the back surface side of the supply/discharge plate to be led out.