To provide a battery capable of easily dismantling a container while keeping airtightness of the container.

In the battery having an electrode body 2 and a container 10 for housing the electrode body 2, the container 10 is provided with a storage section 11 having an opening at an upper surface and a cover section 12 for blocking an opening surface of the storage section 11 and the container 10 is sealed by joining the storage section 11 and the cover section 12. Groove sections 13, 13 are continuously arranged on the container 10 along a connection section 30 between the storage section 11 and the cover section 12.