An energy storage apparatus includes an energy storage device containing a case where a corner portion is formed by a first wall portion and a second wall portion, an opposedly facing member which opposedly faces the first wall portion, and an insulator covering at least a region of the opposedly facing member which opposedly faces the energy storage device. The opposedly facing member contains a body disposed along the first wall portion and an extension portion extending from the body along the second wall portion. The insulator contains a cover portion which extends to a distal end of the extension portion from a boundary position between the extension portion and the body along an opposedly facing surface of the extension portion which opposedly faces the second wall portion, is folded back at the distal end, and extends along an outer surface of the extension portion opposite to the second wall portion. A first inner surface of the cover portion which opposedly faces the opposedly facing surface of the extension portion includes a projecting portion which projects toward the opposedly facing surface.