A lighting device, a lighting attachment device, and a method of manufacturing a lighting cover having a film coated with an optical-scattering agent are provided. The lighting device includes: a lighting unit having a lighting cover, the lighting cover having an adjustable degree of optical scattering; and a control unit configured to adjust the lighting cover to an appropriate degree of optical scattering according to the growth state of a cultivation subject. The method for manufacturing a lighting cover includes: partitioning a lighting cover of a synthetic resin material into a plurality of scattering zones; and coating an optical-scattering agent on the lighting cover such that each of the scattering zones has a different degree of optical scattering.