A film-shaped optical waveguide production method which ensures easy production of individual film-shaped optical waveguides without the need for cutting and stamping. A plurality of film-shaped optical waveguide formation regions are defined on a substrate (1). Then, film-shaped optical waveguides (W) are produced in the respective film-shaped optical waveguide formation regions by forming under-cladding layers (2) in the respective regions and forming cores (3) on the respective under-cladding layers (2). Subsequently, the film-shaped optical waveguides (W) are separated from the substrate (1).