Provided is an image sensor lighting unit including at least one light guide extending in a main scanning direction; a first light source group facing a first end surface of at least two end surfaces of the at least one light guide in the main scanning direction; and a second light source group facing a second end surface of the at least two end surfaces. The first light source group includes a first light source that emits light having a predetermined wavelength band. The second light source group includes a second light source that emits light having the wavelength band. An X-coordinate of the first light source in a corresponding XY-coordinate system is equal in absolute value to an X-coordinate of the second light source in a corresponding XY-coordinate system, with the at least one light guide viewed from the first end surface side in the main scanning direction.