A negative electrode material for a power storage device contains a single-phase porous carbon material capable of electrochemically occluding and releasing lithium ions, the single-phase porous carbon material has a BET specific surface area of not less than 100 m2/g, and a cumulative volume of pores having a pore diameter of 2 nm to 50 nm in a pore diameter distribution of the single-phase porous carbon material is not less than 25% of a total pore volume.