Angular intensity distribution shaping member and the surface light source device

The surface light source device 100 includes a surface-emitting light guide plate 15, the first light source 18, second light source 101 and the angular intensity distribution shaping member 110. The surface-emitting light guide plate 15 has a first light incident surface 15c, emits light beams L11, L12 incident from the first light entrance plane 15c as planar light L14. The first light source 18 is disposed opposite the first light entrance plane 15c, it emits a first light beam L11 toward the first light entrance plane 15c. The second light source L101 emits a second light beam L12 having a narrow angular intensity distribution than the first light beam L11. Angular intensity distribution shaping member 110 has a second light incident surface 110a, and guides the first light incident surface 15c and the second light beam L12 incident from the second light incident surface 110a, of the second changing the angular intensity distribution of the light beam L12.