A manufacturing method for a secondary battery according to the invention includes an assembling step in which an insulating member having an insulating property is assembled to an electrode body, the insulating member having a first inclined portion and a second inclined portion provided so as to face each other in one end of the insulating member, as well as a gap provided between the first inclined portion and the second inclined portion. In the first inclined portion and the second inclined portion, inclined surfaces are formed on surfaces of the first inclined portion and the second inclined portion on sides facing each other, and are inclined in a direction in which the first inclined portion and the second inclined portion are separated from each other as the first inclined portion and the second inclined portion extend to tip sides.