An optical waveguide device which includes an optical waveguide part and a photonic device mounting part is provided. A mask to form a pedestal block on which a light emitting device is mounted is patterned after high-temperature annealing. Thus, there is no influence on the mask, even if the device undergoes the heat treatment at a high temperature during the manufacturing process. This enables formation of the pedestal block with high accuracy. Therefore, it is possible to achieve an optical coupling with high accuracy in mounting a light emitting device on the pedestal block.