We have fabricated vertical type organic thin film transistor (OTFT) using solution-processible electrically conductive poly(3-hexylthiophene) (P3HT) as a p-type organic material. The layers of OTFT consisting of ITO/P3HT/Al gate/P3HT/Au were fabricated by vacuum evaporation and spin coating method onto the Indium Tin Oxide (ITO) coated glass. The effects of drain electrode and thermal annealing of P3HT on the current-voltage and on-off ratio of transistor were investigated. The vertical type OTFT using Au as drain electrode after the thermal annealing showed high current of -0.16 mA and on-off ratio of 16.0 at a low gate voltage of +2.0 V.