There is provided a lighting device capable of forming a line beam having a sufficiently long length in an irradiation direction. A distance between a light source end close to irradiation surface and irradiation surface is greater than a distance between lens center and irradiation surface by using light source in which a plurality of light emitters is arranged in a straight line and lens of which an emission surface having a constant curvature is corrected by an odd function. Accordingly, a shape of light source is formed on irradiation surface, and thus, it is possible to form line beam having the sufficiently long length in the irradiation direction.