To provide a planar light unit that optically and mechanically connects a light-emitting device and a light guide plate to each other in a stable manner so as to improve luminous efficiency and brightness uniformity on a light exit surface. A planar light unit 40 includes: a light guide plate 2, which includes a light incident portion 2f on a side edge of the light guide plate 2; a light-emitting device 3, which is configured to emit light into an inside of the light guide plate 2 through the light incident portion 2f; and a light source board 4, on which the light-emitting device 3 is mounted. The light incident portion 2f includes a recess 2a and a reflecting-shaped portion 2b. A flexible resin 6, which has a light-transmitting property and a flexibility, is disposed between a light incident surface 2c, which is formed on the recess 2a, and the light-emitting device 3.