An optical waveguide 30 having a bending groove 34 parallel to two long sides of a rectangular shape thereof. The optical waveguide 30 is bent along the bending groove 34 so as to come into close contact with a frame of an optical touch panel. This makes it possible to attach the optical waveguide 30 to the frame without misalignment during assembly. Therefore, the optical waveguide 30 can emit light beams in a direction perpendicular to one side of a rectangular display screen opposed to one long side of the rectangular shape thereof. Further, the width of the frame of the optical touch panel 30 can be made smaller than that of the optical waveguide 30. This makes it possible to achieve reduction in the width of the frame of the optical touch panel.