Organic field effect transistor

An organic field effect transistor comprising an organic semiconductor layer constituting a current path between a source electrode and a drain electrode wherein the organic semiconductor layer is made of a conjugated polymer having a depletion layer, and a conductivity of the organic semiconductor layer is controlled by using a gate electrode, and a gate insulation layer is disposed between the gate electrode and the organic semiconductor layer, wherein the depletion layer is formed by contacting a reductive material being capable of forming Schottky contact with the organic semiconductor layer made of the conjugated polymer, wherein the reductive material is deposited on the organic semiconductor layer with an average film thickness of 10 nm or less.