To facilitate handling, improve reliability, and facilitate mass production.

This manufacturing method for a packed battery is provided with a process for storing and attaching batteries 7 and a wiring substrate 9 in a case main body 4 in which a cutout part 10 for making an adhesive flow is disposed on a side wall of an end side of an opening 4a; a process for forming an outer case in such a way that connected parts of cover bodies 5a, 5b are engaged and sealed to the opening 4a of the case main body 4, and furthermore assembling a battery pack by connecting a wiring circuit 9 to an outside connecting terminal 8 arranged and led out to a wall of the outer case wall part; and a process for filling the adhesive from the cutout part 10 where the adhesive of the case main body 4 flows in, and an integratedly joining the case main body 5 with adhesive layers 6 by interposing the adhesive layers 6 between their engaging surfaces of cover bodies 5a, 5b.