An energy storage device is provided in which a decrease in power caused by repetitive charge-discharge in a high-temperature environment is suppressed. In the present embodiment, an energy storage device and a method for manufacturing the energy storage device are provided, the energy storage device including an electrode which includes: an active material layer including a particulate active material; and a conductive layer layered on the active material layer and including a conduction aid. An average secondary particle diameter of the active material is 2.5 μm or more and 6.0 μm or less. A surface roughness Ra of the conductive layer on a side on the active material layer is 0.17 μm or more and 0.50 μm or less.