Provided is an energy storage device which includes: an electrode assembly including a positive electrode and a negative electrode respectively including a non-coated region having a metal foil; current collectors each having a support portion which is made to overlap with the non-coated region; and opposedly facing supports each configured to clamp the non-coated region cooperatively with the support portion, wherein at least one of the non-coated region, the support portion and the opposedly facing support includes a conductive layer having non-oxidizing property or hardly-oxidizable property, the conductive layer covering at least one surface out of a surface of the non-coated region facing the support portion, a surface of the non-coated region facing the opposedly facing support, a surface of the support portion facing the non-coated region, and a surface of the opposedly facing support facing the non-coated region.