Optical body and light emitting device

There is provided a light emitting device that can be used as a light guide plate and has an excellent antireflection function to extraneous light, and an optical body includes: a base material; a macro concave-convex structure that is formed on one surface of the base material and emits internally propagating light that is injected in an inside of the base material from a side surface of the base material, from another surface of the base material; and a micro concave-convex structure formed periodically to follow each of both surfaces of the base material and a surface of the macro concave-convex structure, and having an average period of concavity and convexity of less than or equal to a wavelength of visible light. The surface of the macro concave-convex structure has an inclined surface, and an arrangement of the micro concave-convex structure is a zigzag arrangement.