A surface emitting device includes a light guide plate having a light outgoing surface and a reflection surface and an LED light source that includes an LED element provided so that light from the LED element enters the light guide plate through a light incoming end surface of the light guide plate. The light guide plate includes a concave portion corresponding to the LED element on a side of the reflection surface just in front of the LED light source. The concave portion has dimensions in which a width of the light guide plate is equal to or larger than a width of a light outgoing surface of the LED element, and a depth from the reflection surface in a thickness direction of the light guide plate is set so that the concave portion does not overlap with a region opposed to the light outgoing surface of the LED element.