ELECTRICITY STORAGE DEVICE

The electricity storage device (30) includes: a first oxide semiconductor layer having a first conductivity-type first oxide semiconductor (14); a first charge layer (16) disposed on the first oxide semiconductor layer (14), and composed by including a first insulating material and a first conductivity-type second oxide semiconductor; and a third oxide semiconductor layer (24) disposed on the first charge layer (16). The third oxide semiconductor layer (24) has hydrogen and a second conductivity-type third oxide semiconductor, and a percentage of the hydrogen with respect to a metal constituting the third oxide semiconductor is equal to or greater than 40%. The embodiments provide an electricity storage device capable of increasing an electricity storage capacity per unit volume (weight).