An organic transistor is capable of emitting light at high luminescence efficiency, operating at high speed, handling large electric power, and can be manufactured at low cost. The organic transistor includes an organic semiconductor layer between a source electrode and a drain electrode, and gate electrodes shaped like a comb or a mesh, which are provided at intervals approximately in the central part of the organic semiconductor layer approximately parallel to the source electrode and the drain electrode. The organic semiconductor layer consists of an electric field luminescent organic semiconductor material such as compounds of naphthalene, anthracene, tetracene, pentacene, hexacene, a phthalocyanine system compound, an azo system compound, a perylene system compound, a triphenylmethane compound, a stilbene compound, poly N-vinyl carbazole, and poly vinyl pyrene.