A polymer optical waveguide module has a submount, one of an emitter and a detector and an optical waveguide. The optical waveguide is a polymer optical waveguide film obtained by using a mold, which has, on an identical end portion thereof, an optical-path converting mirror surface and an alignment surface. One of the emitter and detector as well as the polymer optical waveguide film are held on the submount. The polymer optical waveguide film is aligned on the submount by use of the alignment surface.