The present invention provides a nanostructure on an upper surface of which a small-diameter carbon nanotube (CNT) is formed and which improves an adhesive strength between a substrate and the CNT while controlling an orientation of the CNT, and a method for manufacturing the nanostructure. The nanostructure includes a substrate 101, a porous layer 102 formed on the substrate 101 to have a fine pore, a fine pore diameter control layer 103 formed on the porous layer 102, and a carbon nanotube 701 formed to extend from the fine pore defined by the fine pore diameter control layer 103, and one end of the carbon nanotube is fixed by the fine pore diameter control layer 103. It is preferable that the substrate 101 and the fine pore diameter control layer 103 be electrically conductive. It is preferable that the porous layer 102 be an anode oxide film. It is preferable that a melting point of the fine pore diameter control layer 103 be 600° C. or higher.