Disclosed is a negative electrode active material which is capable of occluding and releasing lithium, and has high reversible capacity and reduced initial irreversible capacity. This negative electrode active material includes a granulated substance, in which a composite containing nanosize conductive carbon powder and tin oxide powder contacting the surface of the conductive carbon powder in a highly dispersed state and an aggregate selected from the group consisting of graphite and nongraphitizable carbon are aggregated. The electrochemical decomposition of electrolytic solution is suppressed due to a reduction in the area where the carbon material in the granulated substance and the electrolytic solution are in contact, resulting in a significant reduction in the initial irreversible capacity of the negative electrode active material.