A filament lamp includes multiple filament assemblies having filaments connected to paired leads, arrayed in order within a light emitting tube and following a tube axis thereof. Each lead is electrically connected in a seal area. Each filament is powered independently. The light emitting tube includes insulating walls or inner tubes between the filaments and leads that have openings through which the leads pass, and located along the tube axis in proximity to the inner wall of the light emitting tube. Multiple lead accommodation spaces corresponding to the number of leads are provided in the light emitting tube by the insulating walls with each lead passing through an opening in the insulating wall and placed without short circuits in its lead accommodation space.