Fine particle producing apparatus and fine particle producing method

A fine particle producing apparatus includes a reaction chamber extending vertically from the lower side to the upper side; a material supply device which is connected to a central part on one end side of the vertically lower side inside the reaction chamber and supplies a material particle into the reaction chamber of a vertically upper side from a material supply port; a first electrode arrangement region which protrudes in an inward radial direction to be disposed on an inner peripheral wall in the reaction chamber which is vertically above the material supply device, and includes a plurality of lower electrodes to which AC power is applied; a second electrode arrangement region which protrudes in an inward radial direction to be disposed on an inner peripheral wall in the reaction chamber which is vertically above the first electrode arrangement region, and includes a plurality of upper electrodes to which AC power is applied; a collector which is connected to the other end side in the reaction chamber of the vertically upper side so as to collect fine particles; a power source which is capable of changing a frequency of AC power applied to at least one of the lower electrode included in the first electrode arrangement region and the upper electrode included in the second electrode arrangement region; and a controller which sets the frequency of AC power applied to the lower electrode as a frequency equal to or higher than a frequency of AC power applied to the upper electrode, in which a fine particle is generated from the material particle by generating arc discharge by the lower electrode and the upper electrode, and generating plasma in the reaction chamber.