The present invention is a secondary battery, including: an electrode group that includes a positive electrode and a negative electrode, an electrolyte, and a battery cell container that contains the electrode group and the electrolyte and that is sealed, wherein: an adhesive layer for trapping foreign matter present inside the battery cell container is disposed in the battery cell container by exposing at least part of the adhesive layer so as to allow the adhesive layer to come into contact with the electrolyte.