A scanner module and an image scanning apparatus employ an illuminator that includes at least one light emitting diode, a light guide to change the direction of the light from the light emitting diode, and a light source holder to which the light emitting diode is mounted, the light source holder being positioned in relation to the light guide such that the light source holder covers an incidence face of the light guide, on which the light from the light source is incident, the surface of light source holder facing the incidence face reflecting light incident thereupon. The reflection of light by the light source holder reduces the possibility of leakage of light, and can enhance luminous intensity of light of the illuminator.