Disclosed is an organic electronic device, in which a semiconductor layer and source/drain electrodes may be formed from materials of the same type, suitable for a room-temperature wet process, and thus have surface properties similar to each other, thereby decreasing contact resistance between the semiconductor layer and the source/drain electrodes. The materials for formation of the semiconductor layer and source/drain electrodes may be organic semiconductor type materials obtained by adding carbon-based nanoparticles to organic semiconductor materials in predetermined or given amounts. As such, the conductivity of a semiconductor or conductor may vary depending on the amount of carbon-based nanoparticles.