An area light source device includes a light source, a light guide including a first side surface on which emission light from the light source is incident, and a first major surface and a second major surface, which are opposed to each other and from which the incident light on the first side surface emerges, an optical sheet that is disposed on the second major surface side of the light guide and has a reflective surface on a side thereof that is opposed to the second major surface, and a film member that is disposed between the light guide and the optical sheet, has light transmissivity and has a projection-and-recess-shaped portion on a surface thereof.