An oxide crystalline thin film is used to provide an oxide semiconductor thin film that has comparatively high carrier mobility and is suitable as TFT channel layer material. Oxide semiconductor thin film is obtained by performing an annealing process on an amorphous oxide semiconductor thin film comprising an oxide including indium and titanium where the titanium content is 0.005 to 0.12 by a Ti/In atomic ratio at a heating temperature of 250° C. or greater and processing time of 1 minute to 120 minutes. The oxide semiconductor thin film is crystalline and comprises only the In2O3 phase of bixbyite type structure, and has carrier density that is 1×1019 cm−3, and carrier mobility that is 1 cm2/Vsec or greater.
