To mitigate the vignetting of the illumination light as caused by structure, be not easy for the purpose of significantly illuminating to carry out the difference of the highlights on object and dark portion, lighting device of the invention (4) includes illumination region, has the ejecting end for projecting illumination light It spreads optical component (8), it is circumferentially configured around defined axis, with the incidence end arranged opposite with ejecting end, which is directed at the illumination light while making and spreading from the illumination light of incidence end incidence and guides, and projects from surface And reflecting layer, surface on the inside of its radial direction with diffusion optical component (8) is configured adjacently, by illumination light, lateral reflection, the injection region (A) for spreading the illumination light of optical component (8) become smaller around the angle of axis with incidence end is axially distant to outside radial direction.
