Disclosed is a method for manufacturing an oxide thin film transistor, including: forming a gate electrode on a substrate on which a buffer layer is formed; forming a gate insulation layer on an entire surface of the substrate on which the gate electrode is formed; forming an oxide semiconductor layer on the gate insulation layer; forming a first etch stop layer on the oxide semiconductor layer; forming a second etch stop layer on the first etch stop layer by an atomic layer deposition method; patterning the first etch stop layer and the second etch stop layer, or forming a contact hole, through which a part of the oxide semiconductor layer is exposed, in the first etch stop layer and the second etch stop layer; forming a source electrode and a drain electrode on the first etch stop layer and the second etch stop layer; and forming a passivation layer on the entire surface of the substrate on which the source electrode and the drain electrode are formed.