New-type organic transistors based on the charge injection process at organic/metal interface were proposed and demonstrated. The device was composed of an organic deposited film sandwiched by two metal electrodes and the third stripe-shaped electrode embedded in the organic film. The output current corresponding to collector current was modulated by the applied voltage of the third electrode corresponding to base electrode, and current amplification factor of h_FE reached 20. The transistor operation was attributed to the electron injection caused by accumulation of holes supplied from the base electrode. The current amplification was observed up to about 100 Hz in the frequency response measurement.