Disclosed is a power storage device including a negative electrode and a positive electrode. The negative electrode includes a negative electrode current collector including a common portion and a plurality of protrusions protruding from the common portion, and a negative electrode active material layer which covers a side surface of the protrusion. The positive electrode faces the negative electrode with an electrolyte provided therebetween. In the plurality of protrusions, a distance between adjacent protrusions is a distance with which adjacent negative electrode active material layers are in contact with each other before the capacity of the negative electrode active material layer reaches the theoretical capacity of the negative electrode active material layer by insertion of carrier ions from the positive electrode.