Abstract: A lithium-ion battery manufacturing device and a lithium-ion battery manufacturing method can suppress variation in thickness and shape distortion of a lithium-ion battery. The lithium-ion battery includes a cathode current collector, a cathode active material layer, a separator, an anode active material layer, and an anode current collector that are stacked. The lithium-ion battery has a circular frame member that fixes an outer edge of the separator, which is placed between the cathode current collector and the anode current collector, and that seals the cathode active material layer, the separator, and the anode active material layer. The lithium-ion battery manufacturing device includes: a holder that sandwiches the lithium-ion battery from both sides of the stacking direction; and a sealing device that has a frame-shaped heater, which heat-seals an outer edge of the lithium-ion battery by heating the frame member placed at the outer edge.