An apparatus including: a first bonding unit that at least partially bonds a first separator strip and a second separator strip in a width direction at a first position; a first feeding unit that supplies the first separator strip to the first position; a second feeding unit that supplies the second separator strip to the first position so as to make an angle to the first separator strip; and a third feeding unit that supplies, in synchronization with timing of bonding of the first separator strip and the second separator strip in the width direction at the first position, an electrode sheet to the first position so as to be between the first separator strip and the second separator strip and make an angle to the first separator strip and the second separator strip respectively.