PROBLEM TO BE SOLVED: To provide an optical waveguide device having the high degree of freedom in terms of design such as the forming position of an optical path changing part and restraining the leakage of light and scattering loss, and its manufacturing method. SOLUTION: The manufacturing method for the optical waveguide device is a method for manufacturing the optical waveguide device 100 equipped with a base part 3, a lower clad part 21 arranged on the base part 3, a core part 1 layered on the lower clad part 21 and propagating light, an upper clad part 22 arranged on the core part 1, the optical path changing parts 41 and 42 formed on the base part 3 and changing the optical path of the light propagated through the core part, and includes a core part forming unhardened film disposing stage for disposing a core part forming unhardened film on a layered body equipped with the base part 3, and the lower clad part 21 and the optical path changing parts 41 and 42 formed on the base part 3, a core part forming stage for forming the core part 1, and an upper clad part forming stage for forming the upper clad part 22. COPYRIGHT: (C)2006,JPO&NCIPI