A photoelectronic device capable of maintaining the degree of freedom in designing for dealing with design changes and responding to producing a variety of kinds in a small amount, and the production method are provided: wherein a light emitting element for emitting a light to be a clock signal, a semiconductor chip provided with light receiving portions for receiving the light, and an optical waveguide sheet formed to be a sheet, wherein an outer circumference of a core is covered with a clad, adhered to said semiconductor chip are provided; and the optical waveguide sheet is configured to be irradiated at a light incident portion of a core with a light from the light emitting element and includes one or more T-shaped branch having a vertical opening portion having a vertical inner wall, which is vertical with respect to the direction within a surface of the optical waveguide sheet and becomes a mirror surface for dividing and reflecting the light, and a sloping opening portion having a sloping inner wall, which has an inclination with the optical waveguide direction of the core and becomes a mirror surface for reflecting the light to the direction being out of the surface of the optical waveguide sheet so as to be connected to a light receiving portion at a connection position of each of the lights and each of the light receiving portions.