An optical interconnect structure includes a lens array and a waveguide substrate. The lens array has a dummy lens. The waveguide substrate has a dummy core, a dummy mirror corresponding to the dummy core, and an inspection opening for injecting inspection light into the dummy core to reach the dummy mirror. In the optical interconnect structure, the lens array is mounted on the waveguide substrate such that the dummy lens of the lens array is positioned on the dummy mirror by monitoring inspection light from the inspection opening.