Power storage device

A power storage device comprising:

• a case member made of metal and provided with an insertion hole;
• a terminal member inserted through the insertion hole;
• an electrode body accommodated in the case member and connected to the terminal member;
• and
• a resin member in contact with each of the case member and the terminal member to insulate between the case member and the terminal member,
• wherein the case member includes a surface facing outside and including a region in contact with the resin member, the region including:
• a ring-shaped seal region surrounding the insertion hole, to which the resin member is airtightly firmly fixed;
• and
• a contact region located outside the seal region in radial directions of the insertion hole, with which the resin member is in contact,
• a two-region consisting of the seal region and the contact region has a two-region length, which is a total length of the seal and contact regions, at a two-region length ratio of 3.0 or more, which is a ratio of a maximum two-region length to a minimum two-region length, and
• the seal region has a seal length at a seal length ratio of 1.4 or less, which is a ratio of a maximum seal length to a minimum seal length.