PURPOSE: To precisely manufacture a light control device having a buffer layer only immediate under an electrode in the lessened number of processes.

CONSTITUTION: A buffer layer 3 made of an insulating material and an electrode film 4 made of a conductive material are successively formed on a substrate 1 in which an optical waveguide 2 is formed and a resist film 5 with an optional shape is formed in a part of the electrode film 4. Of the electrode film 4, the part not coated with the resist film 5 is removed and of the buffer layer 3, the part not coated with the electrode film 4 and with the resist film 5 is removed. Consequently, the buffer layer 3 and the electrode film 4 are shaped into the shape of the resist film. Finally, the resist film 5 is removed.