To provide a lighting device which is efficient in using light and has a large rate for changing the illuminated area in the longitudinal direction of the light source.

The lighting device has a light source 31, a first optical component 32 having a surface 32a to emit the light flux input by the light source, a light incident surface 33a the light flux enters from the first optical component, and a second optical component 33 having a reflecting surface 33e provided at the end in the first direction X parallel with the longitudinal direction of the light source to reflect part of the light flux. The area illuminated by the light flux from the second optical component changes by changing the distance between the first and second optical components in the first direction and the second direction Y perpendicularly crossing the first direction. In this lighting unit, the emitting surface of the first optical component has negative refractive power, and the incidence surface of the second optical component has positive refractive power, in the first direction.