To provide a light bulb exerting an environment improving action in addition to a light source function.

A film emitting negative ion such as a film of fine crystals of tourmaline or the like is applied to a glass bulb part of the light bulb to contribute to an effect on a living bodies for example on a relaxation, an effect on reduction or cure of symptoms of various diseases, and an effect on growth acceleration or prolonging lives of animals and plants. In the film emitting negative ion, by using a scattering preventing film material as a main component, a scattering preventing effect of glass broken pieces is made possible in mounting and removing the light bulb on and from an apparatus or the drop of the light bulb.