A nanodevice capable of controlling the state of electric charge of a metal nanoparticle is provided. The device includes: nanogap electrodes 5 including one electrode 5A and the other electrode 5B disposed so as to have a nanosize gap in between; a nanoparticle 7 placed between the nanogap electrodes 5; and a plurality of gate electrodes 9. At least one of the plurality of gate electrodes 9 is used as a floating gate electrode to control the state of electric charge of the nanoparticle 7, which achieves a multivalued memory and rewritable logical operation.