METHOD FOR MANUFACTURING SECONDARY BATTERY

A method for manufacturing a secondary battery having a film package by covering upper and lower sides of a laminate structure constituting a battery with a pair of film materials respectively and bonding the film materials together sequentially in a process direction from one end of the film materials to the other, the method comprising: a first sealing step of overlapping the film materials such that the laminate structure is sandwiched therebetween, and sealing one end of the overlapping part of the films, the one end being located at an upstream of the process direction, and a second sealing step of bonding the overlapped film materials together at one or each of side portions thereof extending along the process direction sequentially in the process direction, while pressing a middle portion of the overlapped film materials sequentially in the process direction to thereby degas an internal space between the film materials, the middle portion being located between the side portions, wherein in the second sealing step, the side end portions are bonded in advance of pressing the middle portion as viewed with respect to a position corresponding to a single straight line orthogonal to the process direction.