A polarizing mask and an apparatus and method for manufacturing an optical device are provided. The polarizing mask capable of being used to manufacture the optical device including an optical layer whose optical axes or light absorption axes are shifted continuously is provided. The optical device manufactured thus can be used to adjust characteristics of light in electronic devices such as display devices, or can be used for various applications requiring a continuous change in an optical axis or light absorption axis, including use of windows or shades of buildings or automobiles.