A nanocarbon separation device includes a separation tank that is configured to accommodate a dispersion liquid including nanocarbons, a first electrode that is provided at an upper part in the separation tank, a second electrode that is provided at a lower part in the separation tank, an evaluation unit that is configured to evaluate a physical state or a chemical state of the dispersion liquid, and a fractionation unit that is configured to fractionate the dispersion liquid based on the physical state or the chemical state.