A power storage material is made by using a fiber material of cellulose molecules obtained from wood, plant fibers (pulp), and the like, and capable of storing electric power of direct current and alternating current, and an ultra power storage body has the power storage material. A power storage material includes a fiber mainly including a fiber derived from at least any one of wood, plant fibers (pulp), animals, algae, microorganisms, and microbial products, and having a large number of recesses and protrusions on a surface. The fiber is preferably crystallized/amorphous fibers, is preferably an amorphous fiber having an atomic vacancy, and preferably has a specific surface area of 10 m2/g or more. Preferably, the large number of recesses and protrusions have a diameter of 1 nm to 500 nm. Preferably, the electric resistance is 100 MΩ or more, and the electric capacity is 5 mF/cm2 or more