A structure of a line lighting device permits a rod-like light guide to be attached to a case without rubbing against the case. An end portion of the rod-like light guide provided with a pin is inserted into an opening in a case main body and pushed down, thus making the pin engage with a recess in the case main body. At this time, a distal end of the rod-like light guide is inserted, to some extent, into an opening in a light emitting unit fixing portion. Subsequently, the rod-like light guide is pushed down and pivoted around the pin so as to be completely contained within the case main body. In this state, the distal end of the rod-like light guide is fitted into the opening and the end face of the rod-like light guide is flush with the outer side face of the light emitting unit fixing portion.