To provide a method for producing a titanium oxide layer which is excellent in adhesion and transparency even when the titanium oxide layer is produced in a short period by the plasma CVD method, is invariable in refractive index after production of the layer and is stable and to provide a titanium oxide layer produced by using the method and an antireflection film which uses the titanium oxide layer in a laminate.

In the plasma CVD method, an organic titanium compound gas and oxygen gas are supplied to a reaction chamber, the gases are discharged and are made to a plasma state, and the titanium oxide layer is laminated on a substrate placed in the reaction chamber. Therein, this method for producing titanium oxide layer uses the plasma CVD method which features that the titanium oxide layer is laminated in the presence of water vapor by supplying water vapor into the reaction chamber besides the organic titanium compound gas and oxygen gas.