A power storage device including a negative electrode having high cycle performance in which little deterioration due to charge and discharge occurs is manufactured. A power storage device including a positive electrode, a negative electrode, and an electrolyte provided between the positive electrode and the negative electrode is manufactured, in which the negative electrode includes a negative electrode current collector and a negative electrode active material layer, and the negative electrode active material layer includes an uneven silicon layer formed over the negative electrode current collector, a silicon oxide layer or a mixed layer which includes silicon oxide and a silicate compound and is in contact with the silicon layer, and graphene in contact with the silicon oxide layer or the mixed layer including the silicon oxide and the silicate compound.