Nonaqueous-electrolyte secondary battery and method of manufacturing the same

The invention offers excellent hermeticity inside a battery being covered with package members (3a, 3b) and avoids sealing failures caused by gaps between sides of lead electrodes (1a, 1b) and the package members (3a, 3b) in sealing parts, in which the lead electrodes are disposed. During a step of sealing between ends of the package members (3a, 3b) and the lead electrodes (1a, 1b) by fusing the sealing members (2a, 2b), or during a step of adhering the fused sealing members (2a, 2b) to the lead electrodes, stripping sheets (4a, 4b) made of a material such that the fused sealing members (2a, 2b) do not adhere to heaters (6a, 6b), are inserted between the package members (3a, 3b), or the sealing members (2a, 2b) and the heaters (6a, 6b). Accordingly, even if the fused sealing members (2a, 2b) are forced our from ends of the package members (3a, 3b), or leak toward the outside, the sealing members (2a, 2b) does not adhere to surfaces of the heaters (6a, 6b) or crumble their shapes.