PURPOSE: To improve lighting efficiency and soften light by using a plurality of petal pieces comprising shape memory resin.

CONSTITUTION: A lighting cover (C) which is detachable to a socket 3 of a lighting fitting (S) is attached to the socket 3 and a bulb 1. The cover (C) comprises a plurality of petal pieces 8... formed from a shape memory resin and is integrated at the base part so as to be easy to be attached to the socket 3. Characteristics of the shape memory resin and laminated structure allow binary-directional reversible changes in the cover, that is, a bud state and a flowering state. When the bulb 1 is lit with the cover set in a bud state by such a composite structure, an open-shape memory resin form body 8a is opened against the closing force of a closed-shape memory resin form body 8b according to its heating temperature so that the cover is turned into a flowering state.