Abstract: An electrode assembly manufacturing device according to the present disclosure includes a transfer unit for transferring an electrode assembly to a sealing position, multiple sealing blocks, and a lower support. The lower support is controlled to move up and down in a first state in which the sealing block is moved forward toward the electrode assembly, so that both distal ends of multiple separators in the longitudinal direction are bent downward and sealed while being in contact with the sealing block. Since the electrode assembly manufacturing device according to embodiments of the present invention heat-seals the end of the separator in a downwardly bent state, it is possible to manufacture an electrode assembly that prevents blocking of the separator when sealing a pouch.