The present invention provides a manufacturing method of an organic semiconductor device comprising a step of transferring an organic semiconductor layer to a gate insulation layer by a thermal transfer at a liquid crystal phase transition temperature of a liquid crystalline organic semiconductor material, and the step uses: an organic semiconductor layer-transferring substrate comprising a parting substrate having parting properties, and the organic semiconductor layer formed on the parting substrate and containing the liquid crystalline organic semiconductor material; and a substrate for forming an organic semiconductor device comprising a substrate, a gate electrode formed on the substrate, and the gate insulation layer formed to cover the gate electrode and having alignment properties which are capable of aligning the liquid crystalline organic semiconductor material on a surface of the gate insulation layer.