A negative-electrode active material for secondary batteries according to one aspect of the present invention comprises: core particles comprising a material which occludes and releases lithium metal; a first layer, which has been formed on the surface of each core particle; and a second layer, which has been formed on the first layer. The first layer comprises at least one substance selected from among amorphous carbon, carbon nanotubes, carbon nanofibers, and electroconductive polymers. The second layer comprises at least one inorganic compound selected from among oxides, phosphoric acid compounds, silicic acid compounds, and boric acid compounds.