Surface light source device, light control device and display device using same, and illumination device

In the present invention, a surface light source device is provided with the following: a first light source unit that has a first light-emitting element and that emits the light from the first light-emitting element; a second light source unit that has a second light-emitting element and that emits the light from the second light-emitting element at an angular distribution wider than that of the light emitted from the first light source; and a light guide that causes the light emitted from the first light source and the light emitted from the second light source to enter from an end face and be emitted from a main surface. The first and second light source units are disposed on one of a plurality of end faces of the light guide, and can be controlled independently to be turned on and off.