The present invention provides a method for production of a single electron semiconductor element (SET) in which a quantum dot is selectively arranged in a nano gap between fine electrodes, whereby the product yield is significantly improved, leading to excellent practical applicability. The method for production of SET of the present invention is characterized in that a solution containing ferritin including a metal or semiconductor particle therein, and a nonionic surfactant is dropped on a substrate having a source electrode and a drain electrode formed by laminating a titanium film and a film of a metal other than titanium, whereby the ferritin is selectively arranged in a nano gap between the source electrode/drain electrode.