A lighting device includes a linear light source extending in a first direction and configured to emit light in a second direction intersecting the first direction to an object; a rod lens apart from the linear light source in the second direction and extending in the first direction, the rod lens configured to transmit the light emitted from the linear light source; and a support portion supporting the rod lens and having: a first surface extending in a third direction intersecting the second direction; and a second surface extending in a fourth direction intersecting the second direction and the third direction. The rod lens is in contact with each of the first surface and the second surface.